Prevent TelecomManager#endCall from ending emergency calls.

Test: Manual test with test emergency number.
Fixes: 132438333
Change-Id: I4c29a707ec06059b984b61da7d0425a6082476aa
(cherry picked from commit 8d57e376b43326db2cb3b51c375ebf2e6ce40840)
diff --git a/src/com/android/server/telecom/TelecomServiceImpl.java b/src/com/android/server/telecom/TelecomServiceImpl.java
index ea55e63..ded42db 100644
--- a/src/com/android/server/telecom/TelecomServiceImpl.java
+++ b/src/com/android/server/telecom/TelecomServiceImpl.java
@@ -1580,6 +1580,11 @@
         }
 
         if (call != null) {
+            if (call.isEmergencyCall()) {
+                android.util.EventLog.writeEvent(0x534e4554, "132438333", -1, "");
+                return false;
+            }
+
             if (call.getState() == CallState.RINGING) {
                 call.reject(false /* rejectWithMessage */, null, callingPackage);
             } else {