Add config option to enable links to Cell Broadcast app.

Add "config_cellBroadcastAppLinks" internal boolean config item,
defaulting to false. For devices with the Cell Broadcast app,
setting this config option to true will add a menu item to the
MMS app to jump to the list of received cell broadcasts, and a
preferences item to Settings to jump to cell broadcast settings.

Bug: 6709985
Change-Id: I9fe1919e6d76ba1dfe1e1381e2c38ecdd5e0a867

Author: Jake Hamby

core/res/res/values/config.xml

@@ -862,4 +862,7 @@
          [bootmode]:[original USB mode]:[USB mode used]-->
     <integer-array translatable="false" name="config_oemUsbModeOverride">
     </integer-array>
+
+    <!-- Set to true to add links to Cell Broadcast app from Settings and MMS app. -->
+    <bool name="config_cellBroadcastAppLinks">false</bool>
 </resources>

core/res/res/values/public.xml

@@ -243,6 +243,7 @@
   <java-symbol type="bool" name="config_allowActionMenuItemTextWithIcon" />
   <java-symbol type="bool" name="config_bluetooth_adapter_quick_switch" />
   <java-symbol type="bool" name="config_bluetooth_sco_off_call" />
+  <java-symbol type="bool" name="config_cellBroadcastAppLinks" />
   <java-symbol type="bool" name="config_duplicate_port_omadm_wappush" />
   <java-symbol type="bool" name="config_enable_emergency_call_while_sim_locked" />
   <java-symbol type="bool" name="config_enable_puk_unlock_screen" />