Return jobject when getting android Java Surface

This logic is originally borrowed from similar API from shim_gvr API
where we cannot explicity deps on JNI.h in the public header. This
constrain no longer exists as libdvr is an Android platform library.

Bug: 2013449
Test: Built libdvr
Change-Id: Ide72f5fb706cd24e13507749216d7708f1f40fcc