Update AP signal strength on signal level changed

Patch related to bug GMIN-1381 "The AP signal strength is display
different in notification bar and WIFI settings"

On behalf of Ernest P Chen:
Update all access points when reacting to a broadcast that the signal
level changed.

Change-Id: If690212b9d4640d236747eacef9a4ac8c4c98cd9
Signed-off-by: Frederic Danis <frederic.danis@intel.com>
Signed-off-by: Yong Yao <yong.yao@intel.com>
Fix memory leak issue in application settings

If opening Main menu->Settings->Apps, and rotating the phone
about 50 times, Settings force closes and out of memory occur.
This is because after ManageApplications onDestroy, references
of ApplicationsState have not been release. So, they will not
be garbage collected. It leads to OOM and force close. To
avoid this we need to release the references of
ApplicationsState when ManageApplications onDestroy.

Also, when exiting ManageApplications or InstalledApps in
Settings there is a memory leak due to not releasing some
objects. This fix releases the Session objects to avoid
memory leak.

Change-Id: Icca7100bded0653a4ec7f2b4bd48a29262432a3b
Change check for syncActive

In Manage Account settings if account is in syncing state
option provided to user is "sync now" which should be
"Cancel sync".

syncActive is set to true if getCurrentSyncsAsUser() returns
an empty list which means there are no active syncs.

syncActive should be set to false if getCurrentSyncsAsUser()
returns an empty list.

Change-Id: If78247a90bbca3e1a12553b6facb1315321f52cf