Suppress deprecation warning in CastShellActivity.

Suppress deprecation warning in CastShellActivity.

setStreamMute() was deprecated in Marshmallow, but this
invocation is restricted to Lollipop. Move the logic into
a private method and annotate it with @SuppressWarnings.

BUG=Internal b/31140436
TEST=Build cast_shell_apk

Committed: https://crrev.com/ba8e89e88c6fcc6fbf3eb3842df907a8c9bd9620
Cr-Commit-Position: refs/heads/master@{#418440}

[Simeon, 2016-09-13 21:11:47]

sanfin@chromium.org changed reviewers:
+ halliwell@chromium.org, sanfin@chromium.org, slan@chromium.org,
tsunghung@chromium.org

[Simeon, 2016-09-13 21:11:47]

Starting to clean up the lint errors in Chromecast. This is just the beginning.

[halliwell, 2016-09-13 23:46:19]

On 2016/09/13 21:11:47, Simeon wrote:
> Starting to clean up the lint errors in Chromecast. This is just the
beginning.

lgtm

[slan, 2016-09-13 23:52:31]

lgtm

[Simeon, 2016-09-13 23:59:47]

The CQ bit was checked by sanfin@chromium.org

[commit-bot: I haz the power, 2016-09-14 00:00:38]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-14 00:40:18]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-09-14 00:42:04]

Description was changed from

==========
Suppress deprecation warning in CastShellActivity.

setStreamMute() was deprecated in Marshmallow, but this
invocation is restricted to Lollipop. Move the logic into
a private method and annotate it with @SuppressWarnings.

BUG=Internal b/31140436
TEST=Build cast_shell_apk
==========

to

==========
Suppress deprecation warning in CastShellActivity.

setStreamMute() was deprecated in Marshmallow, but this
invocation is restricted to Lollipop. Move the logic into
a private method and annotate it with @SuppressWarnings.

BUG=Internal b/31140436
TEST=Build cast_shell_apk

Committed: https://crrev.com/ba8e89e88c6fcc6fbf3eb3842df907a8c9bd9620
Cr-Commit-Position: refs/heads/master@{#418440}
==========

[commit-bot: I haz the power, 2016-09-14 00:42:04]

Patchset 1 (id:??) landed as
https://crrev.com/ba8e89e88c6fcc6fbf3eb3842df907a8c9bd9620
Cr-Commit-Position: refs/heads/master@{#418440}