Revert "Load MediaPlayer2 implementation with a linker namespace."

This reverts commit 6ac67f7293648405c623889b62ad3d2e384f5110.

Reason for revert: This change is no longer needed thanks to upcoming
                   native_loader change for applying linker namespace.

Bug: 112766913
Test: build and boot
Change-Id: Idb29b6cd6a4baaf791b67e6e7fc3a97f98292be4
3 files changed