Move aggressive allocation to @SystemApi, which means we can hide the "flags" API variants. Remove UUID APIs, since we should use existing Serializable APIs. Relax permission checks to allow apps to ask for their own stats. Improve docs. Test: cts-tradefed run commandAndExit cts-dev -m CtsAppSecurityHostTestCases -t android.appsecurity.cts.StorageHostTest Bug: 37534687, 37534941, 37718184, 37738770 Change-Id: I6a763fb3ab3169c8d3329765bb31e1ee08d9ced7