libaudioeffect_jni: GREF leak fix for JB

- Excessive JNI global reference in AudioEffects.
- Global references created during native setup
  are not deleted.
- Global references are deleted in setup failure
  and during native release.

(cherry picked from commit a04a2bf4563dc20c52f4d4239e01f80b220077a5)
CRs-fixed: 413633

Change-Id: Ia4340a2128850101b394e00c8e1db9db49f516fd