Use proper System Icon identifier for navring

Change-Id: I924fba4776e3953b572445d0701b92d6712e0e67
Do not show up navring on home longpress on navbar

if the user set a custom action on longpress

Change-Id: I659e15e7f9f28e0a0db020e414b99409742c5e2e
Fix possible QS NPE if navbar was not set

Change-Id: Id66b3afdc1bdb73f827d7a055f6c2926057f3016
Merge remote-tracking branch 'slim/jb4.2' into kang