Update list of output files in vr_window_manager hidl genrule

The output files in the android.dvr.composer@1.0_genc++_headers rule
is not correct, which causes ninja to rebuild the rule on every
incremental build.  Fix the list of files to match what is actually
created.

Bug: 33554989
Bug: 35562758
Test: builds, but doesn't rebuild on every incremental build
Change-Id: I2938ad02b8feade4de6d8a5cc969f37e793e93a8