commit 8c329af634dd3d94c07bbb2e7e295946ec9f35f0
author Sheng Wang <sheng.x.wang@sonymobile.com> Fri Aug 19 17:09:32 2016 +0800
committer Andrew Sapperstein <asapperstein@google.com> Thu Jun 01 16:35:03 2017 -0700
tree fc44b9a78967729d50ad578132f2fe6f397937e6
parent fbc9035bcde707cc5f38b4d06bc91e92d5213cae

Volume can not be updated in Sound&notification

After "onActivityPause()" is invoked and "onActivityResume()"
is invoked again, "mVolumizer" is not empty object,
so volume is not updated.

To fix this issue, set "mVolumizer" is null in "onActivityPause()",
if "onActivityResume()" is invoked again, recreate "mVolumizer"
and update volume.

Bug: 37558283
Test: manual, cherrypicking from AOSP
Change-Id: Id91064ea32305b5bf203f34e31988ac923beee6d