Fix memory leak in system_server when screen on/off

Change-Id: I3ed7be519fc9301dd45d162773a6d0d62de12d76
Make "SD Card removed" notification dismissible if the removed SD Card is not the primary storage

The Galaxy S uses the "external SD Card" as the extended storage
and it the notification should be dismissible as it's okay not
to have it.

Additionally, this patch also not hide the USB storage mount dialog
if the removed storage is not the primary storage

Adapted for CM 11

This also includes this commit by @pawitp

https://github.com/CyanogenMod/android_frameworks_base/commit/d07929e4f7182b1684b8a7ed89c58c177ae12c93

Change-Id: I8bab6573766dea68afc919d5fdb3aa606404c2fa