Fix problem where PhoneWindowManager waits for keyguard to draw

This fixes a problem where PhoneWindowManager times out waiting
for keyguard to draw when it's disabled.  Instead, we pass a null
token back which allows PhoneWindowManager to continue.

Fixes bug 11190932

Change-Id: I041ea1d88dca681476d9477a3aab54559976b312
Keyguard: We need to ensure that keyguard is showing as well to set the token

Google fix

https://github.com/SlimRoms/frameworks_base/commit/021806ec33f5f59567f3bb3af135b2a1d88c0951

fixes what it is meant to fix.

But still we need to ensure if the keyguard eg is disabled by 3rd party
apps or the keyguard is not showing due of other reasons to inform PhoneWindowManager over the token
not to wait to draw for the Keyguard and go ahead.

Fix:
Just check for isShowing in addition to the check if KeyGuard is disabled

Change-Id: I5f017a6ccebf12dc717fb6d44802a1c1fee15abc