Fix regression in ListView click handling

Regression caused by patch a607223f34

If an item click handler results in the ListView becoming detached
from the window, the performClick runnable could be executed twice.
Null out the mTouchModeReset runnable before running the click handler
so that it is not run by the detach handler.

Change-Id: I2fab60232027bb4876f9912088e0ffb9b17d308c
avoid crashing system serer process

Context#unregisterReceiver will throw IllegalArgumentException
if the receiver has already unregistered.

In GlobalAction class, when SilentModeAction is changed, it will
close the dialog with some delay. So there is a possibility
that it would unregistere again for the same receiver if a user
changes slient mode againand again. System must not crash in such
a case.

Change-Id: I33662feb48a770d39a8413901ec77ac1acd16bc7
Fix possible integer overflow in MtpStorage

When converting the MB value MtpReserveSpace value to bytes there is a
possible integer overflow since 3 integer values are multiplied, even
though the result is stored in a long variable. This would be visible when
the value is more than 2 GB. This is solved by making the constants
longs instead of ints.

Change-Id: I799129f7076a6e331cece17b5c05aed210499648
Fix Watchdog HeartbeatHandler to run on correct thread

The HeartbeatHandler for the System Server Watchdog has been running
on the wrong thread due to a race condition in initialization.  It's
designed to run on ServerThread, so that it can catch lockups in the
main looper of the System Server.  It has been running on
ActivityManagerThread instead, so it does not detect lockups on the
ServerThread as it should.

ActivityManagerService is calling Watchdog.getInstance() before
ServerThread calls Watchdog.getInstance().init(), so the handler is
being bound to the ActivityManagerThread instead of the ServerThread.

Explicitly bind HeartbeatHandler to ServerThread, so that the Watchdog
catches lockups on this critical thread.

Change-Id: Iccb184ac3adb817feb86ed4ee0e50e443bf74636
Use normal holo instead of light for ResolverActivity Dialogs

Change-Id: I2e47c910bf9923631987692eed53845bc5f33bf9