Telephony(MSIM): Add StatusBar support for MultiSim.

 -Add support for Signal Strength icon display for MultiSim
  Add support for NO SIM icon support for multiple SIMs.

Display dual subscription info in notification panel
  -Show subscription information for both subscriptions
   relevant to the sim state. if sim state is ready show
   operator name, if card absent, show no sim message,
   if UE is in airplane mode, show airplane mode message.

Clear data activity icon when disconnected
  -If data is disconnected before data activity becomes none,
   then clear up/down arrow icon by reset the data activity icon.

Add support for ro.config.combined_signal
  -Add support for ro.config.combined_signal. This property is being used
   to consider data service state for signal display.
   When ro.config.combined_signal is not set to false, we will display
   CS/PS signal strength whichever is available.

Change-Id: I11fb6ed37e7ba40b8db7840feedd109557128758
(cherry picked from commit 37ee8216eba253a61f9836b12f65bfe00f38e46c)
(cherry picked from commit 1e706857e70a03d2139fe1a8416321d603e008b6)

Conflicts:

	packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java