Remove NdkJavaVMHelper.h from NDK directory

NdkJavaVMHelper.h is not a valid NDK header. Replace this one with
NdkJavaVMHelperPriv.h in the cpp directory.

Bug: 149578834
Test: NativeDecoderTest
Change-Id: I07ddec4d31ae84bf4a739fcf512859f794cb1baa
3 files changed