Strip META-INF/services from implementation jars when using as header jars

If a header jar couldn't be built (for example when an API generating
annoation processor is in use) the implementation jar is reused as the
header jar.  If the implementation jar contains an annotation processor
listed in META-INF/services/javax.annotation.processing.Processor then
later javac executions with the implementation jar in the classpath
could attempt to run the annotation processors unexpectedly.  Remove
the META-INF/services directory when using an implementation jar as
a header jar.

Bug: 290933559
Test: builds
Change-Id: I40d48644bc5a09a9564dc2c4b38f627edd00fcf8