Add NULL check in updateProxyConfig

If the exclusionList was null in updateProxyConfig the VM would
crash when converting it to a UTF8 string. Avoid this by adding a
null check.

Change-Id: I0d8106fd54385bd9ae9c652a6c67d459a119cf2b
Fix preference puts with "null" values.

Null values were being written out as <null /> elements in the
XML prefs file (as expected). This allowed the getFoo() functions
to work correctly because they treated null values as missing mappings
but containsKey would fail.

bug: https://code.google.com/p/android/issues/detail?id=64563
Change-Id: I1f466d01db96bf26e208d4fed3a6f257228bea5d
onAccountsUpdated shouldn't be called back after listener unregistered

There is a problem of AccountManager that onAccountsUpdated() is
called back even after the OnAccountsUpdatedListener is unregistered.
It may cause application crash.

For example, when rotating a tablet 180 degree with Settings apk
running, com.android.settings.Settings is re-launched 2 times
successively. (Destroy->Create->Destroy->Create)
It repeats adding&removing OnAccountUpdatedListener.

When dialog was being opened in the following cases,
NullPointerException at BackStackRecord.getBreadCrumbTitle()
was happened on 10 inch tablet which has 2 panes on Settings.
* Settings > Language&input > Language
* Settings > Language & input > Text-to-speech output > Speech rate
* Settings > Wi-Fi > Menu > Advanced > Keep Wi-Fi on during sleep
* Settings > Wi-Fi > Menu > Wi-Fi Direct > Rename device

This fix prevents the undesirable callback.

Change-Id: I081f69c90539cca821cf686b4587495135f375e4
Remove unnecessary updateSurfaceScreenOn call.

This change stops updateSurfaceScreenOn() from being called one time
right after another. It's called at the end of stayAwake(boolean awake),
which is called right before updateSurfaceScreenOn() in release().

Change-Id: I3e5db322f0abce0cd37320a103015ba72dffa64f
Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>