memoize activity manager graphics acceleration check

also account for devices without hardware rendering support

Change-Id: Ib400d85a261d9c5d0fd5770d6cda5f61832cba6b
libaudioeffect_jni GREF leak fix

- excessive jni reference in AudioEffects
- global references created during native setup are not deleted
- global references are dleted in setup failure and during native releases

Changeset 2:
    -fixed whitespace, and rebased on jb42

Change-Id: I3ff54cc3b0c5394e978421dad3a7a257551f776e