Restrict calling in favor of emergency calling - Incoming Cases

The first series of CLs (1/2) that allow for better interactions
between emergency calls and incoming call types. This includes:
1) Disconnecting incoming calls and marking them as MISSED if an
outgoing emergency call is placed before the call is set to active.
2) Not allowing the pulling of external calls while an emergency
call is active and showing a Toast.
3) If a call is in AUDIO_PROCESSING state, hang it up in favor of
a new outgoing emergency call (and mark disconnected call as
MISSED if this is during an initial call screen).
4) If a call is in SIMULATED_RINGING state, hang it up in favor of
a new outgoing emergency call.

Bug: 138741228
Test: manual; atest TelecomUnitTests; atest CtsTelecomTestCases
Change-Id: I74d2b174121fb9c6402caf806d20eb6c5226873a
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 3112abe..2c6a84a 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -335,6 +335,11 @@
     <string name="phone_strings_emergency_call_made_dialog_call_blocking_text_txt">Call Blocking has been disabled to allow emergency responders to contact you.</string>
     <!-- Window title used for the Telecom Developer Menu -->
     <string name="developer_title">Telecom Developer Menu</string>
+    <!-- Some carriers allow an "external" call that has been placed on another device (another
+    tablet, phone, etc...) to be transferred to this device and taken as a call. In
+    the situation that we are already in an emergency call, notify the user that the call can not
+    be taken at this time.-->
+    <string name="toast_emergency_can_not_pull_call">Calls can not be taken while in an emergency call.</string>
     <!-- Label for a switch in the Telecom Developer Menu which is used to enable the enhanced call
          blocking functionality (for test purposes).
          DO NOT TRANSLATE -->