Avoid reallocating FrameBuffer when bitmaps don't need updating.

Close the old FrameBuffer before allocating a new one.

Bug: 384121863
Fixes: 384121863
Flag: build.RELEASE_PACKAGE_MAGIC_PORTRAIT_WALLPAPERS
Test: Drag weather slider. Dump meminfo. Make sure memory doesn't grow.
Repeatly scrube the slider and make sure the app doesn't crash.
Test: atest MagicPortraitWallpapersTests

Change-Id: Ie4f1d61243fed27e3a58c7f2e9fc2d58b46f4b1e
5 files changed