Don't recycle bitmaps we don't own

WallpaperColors#fromBitmap should only recycle the bitmaps
created by itself.

Test: runtest -x tests/Internal/src/android/app/WallpaperColorsTest.java
Fixes: 63758291
Change-Id: I1710bf7118b6ae871442f9606f95ac9c9dbb7d24