frameworks/base: Fix binder parcel leak with getMetadata() API

When VideoView calls getMetadata API of MediaPlayer, parcel object
is getting allocated by MediaPlayer and metadata is created over
parcel object. This metadata object is returned to the VideoView
which is being GC without calling recycle on parcel which was
creating leak in binder virtual memory.

CRs-fixed: 669303
Change-Id: I1e265909ee42d4fabd8b2552668b3d84af994294