Content package with index definitions missing the Oak namespace causes index extraction to fail

<jcr:root xmlns:jcr="http://www.jcp.org/jcr/1.0" xmlns:nt="http://www.jcp.org/jcr/nt/1.0" xmlns:rep="internal"
    jcr:mixinTypes="[rep:AccessControllable]"
    jcr:primaryType="nt:unstructured">
    <foo
        jcr:primaryType="oak:QueryIndexDefinition"
        propertyNames="[foo]"
        reindex="{Boolean}false"
        reindexCount="{Long}1"
        type="property">
    </foo>
</jcr:root>

 org.apache.sling.feature.cpconverter.ConverterException: ConverterException occured on path /jcr_root/_oak_index/.content.xml with message: Failed parsing the index definitions
	at org.apache.sling.feature.cpconverter.ContentPackage2FeatureModelConverter.onFile(ContentPackage2FeatureModelConverter.java:538)
	at org.apache.sling.feature.cpconverter.vltpkg.BaseVaultPackageScanner.traverse(BaseVaultPackageScanner.java:112)
[0m[91m	at org.apache.sling.feature.cpconverter.vltpkg.BaseVaultPackageScanner.traverse(BaseVaultPackageScanner.java:104)
	at org.apache.sling.feature.cpconverter.vltpkg.BaseVaultPackageScanner.traverse(BaseVaultPackageScanner.java:104)
	at org.apache.sling.feature.cpconverter.vltpkg.BaseVaultPackageScanner.traverse(BaseVaultPackageScanner.java:104)
	at org.apache.sling.feature.cpconverter.vltpkg.BaseVaultPackageScanner.traverse(BaseVaultPackageScanner.java:91)
	at org.apache.sling.feature.cpconverter.ContentPackage2FeatureModelConverter.processSubPackage(ContentPackage2FeatureModelConverter.java:404)
	at org.apache.sling.feature.cpconverter.handlers.ContentPackageEntryHandler.processSubPackage(ContentPackageEntryHandler.java:34)
	at org.apache.sling.feature.cpconverter.handlers.AbstractContentPackageHandler.handle(AbstractContentPackageHandler.java:95)
	at org.apache.sling.feature.cpconverter.ContentPackage2FeatureModelConverter.process(ContentPackage2FeatureModelConverter.java:522)
	at org.apache.sling.feature.cpconverter.ContentPackage2FeatureModelConverter.onFile(ContentPackage2FeatureModelConverter.java:536)
	... 14 more
[0m[91mCaused by: org.apache.sling.feature.cpconverter.ConverterException: Failed parsing the index definitions
	at org.apache.sling.feature.cpconverter.handlers.IndexDefinitionsEntryHandler.handle(IndexDefinitionsEntryHandler.java:129)
	at org.apache.sling.feature.cpconverter.ContentPackage2FeatureModelConverter.process(ContentPackage2FeatureModelConverter.java:522)
	at org.apache.sling.feature.cpconverter.ContentPackage2FeatureModelConverter.onFile(ContentPackage2FeatureModelConverter.java:536)[0m[91m
	... 24 more
[0m[91mCaused by: org.apache.jackrabbit.vault.fs.io.DocViewParser$XmlParseException: Unknown namespace prefix used in file name 'oak:index'
	at org.apache.jackrabbit.vault.fs.io.DocViewParser.parse(DocViewParser.java:256)
	at org.apache.sling.feature.cpconverter.handlers.IndexDefinitionsEntryHandler.handle(IndexDefinitionsEntryHandler.java:118)
	... 26 more
[0m[91mCaused by: org.xml.sax.SAXException: Unknown namespace prefix used in file name 'oak:index'
javax.jcr.NamespaceException: Unknown prefix oak[0m[91m
[0m[91m	at org.apache.jackrabbit.vault.fs.impl.io.DocViewSAXHandler.startElement(DocViewSAXHandler.java:312)[0m[91m
[0m[91m	at java.xml/com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.startElement(AbstractSAXParser.java:510)[0m[91m
[0m[91m	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement(XMLNSDocumentScannerImpl.java:374)[0m[91m
[0m[91m	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl$NSContentDriver.scanRootElementHook(XMLNSDocumentScannerImpl.java:613)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:3063)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:836)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:605)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:112)
	at java.xml/com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:534)
	at java.xml/com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:888)
	at java.xml/com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:824)
	at java.xml/com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:141)
	at java.xml/com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1216)
	at java.xml/com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:635)
	at java.xml/com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl.parse(SAXParserImpl.java:324)
	at org.apache.jackrabbit.vault.fs.io.DocViewParser.parse(DocViewParser.java:254)
	... 27 more