Implement FileUtils#contains.
Implement FileUtils#contains.

Partial cherry-pick of changes 4ca728c0 and 21de56a9, which
can't be cherry-picked due to their large surface area.

Change-Id: Ife46e150d360cd5241dea93863141749233c1805

xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base,xorware/android_frameworks_base