Allow Zygote to unmount labeledfs

As "/storage/emulated/0/Android/obb, /storage/emulated/0/Android/data" might be labeledfs (f2fs),
Zygote needs to be allowed to unmount labeledfs while unmounting "/storage".

Here's the warning if we do not add it.
avc: denied { unmount } for scontext=u:r:zygote:s0 tcontext=u:object_r:labeledfs:s0 tclass=filesystem permissive=0

Bug:192989523
Test:adb shell stop; adb shell start; check no warning log
Change-Id: I74ce9bed29ec7da536a261a4fea25628f3d382ef
1 file changed