Remove dependency of EmergencyCallbackModeExitDialog

Change EmergencyCallbackModeExitDialog to use the activity result code
to represent the user choice.

RESULT_OK mean the user click "yes" and exit the Emergency Callback
Mode, otherwise, RESULT_CANCELED will be returned.

This change allows the MobileNetworkSettings decouple from
EmergencyCallbackModeExitDialog.

Bug: 111453847
Test: Build & manual test
Change-Id: I4c2a4843a95858c16e45f13b4f38dc6def3bacf0
diff --git a/src/com/android/phone/EmergencyCallbackModeExitDialog.java b/src/com/android/phone/EmergencyCallbackModeExitDialog.java
index fd6510b..2492f46 100644
--- a/src/com/android/phone/EmergencyCallbackModeExitDialog.java
+++ b/src/com/android/phone/EmergencyCallbackModeExitDialog.java
@@ -52,8 +52,6 @@
     /** Intent to trigger the Emergency Callback Mode exit dialog */
     static final String ACTION_SHOW_ECM_EXIT_DIALOG =
             "com.android.phone.action.ACTION_SHOW_ECM_EXIT_DIALOG";
-    /** Used to get the users choice from the return Intent's extra */
-    public static final String EXTRA_EXIT_ECM_RESULT = "exit_ecm_result";
 
     public static final int EXIT_ECM_BLOCK_OTHERS = 1;
     public static final int EXIT_ECM_DIALOG = 2;
@@ -239,8 +237,7 @@
                             new DialogInterface.OnClickListener() {
                                 public void onClick(DialogInterface dialog, int whichButton) {
                                     // User clicked No
-                                    setResult(RESULT_OK, (new Intent()).putExtra(
-                                            EXTRA_EXIT_ECM_RESULT, false));
+                                    setResult(RESULT_CANCELED);
                                     finish();
                                 }
                             }).create();
@@ -257,8 +254,7 @@
                             new DialogInterface.OnClickListener() {
                                 public void onClick(DialogInterface dialog, int whichButton) {
                                     // User clicked Dismiss
-                                    setResult(RESULT_OK, (new Intent()).putExtra(
-                                            EXTRA_EXIT_ECM_RESULT, false));
+                                    setResult(RESULT_CANCELED);
                                     finish();
                                 }
                             }).create();
@@ -302,8 +298,7 @@
      */
     @Override
     public void onCancel(DialogInterface dialog) {
-        EmergencyCallbackModeExitDialog.this.setResult(RESULT_OK, (new Intent())
-                .putExtra(EXTRA_EXIT_ECM_RESULT, false));
+        EmergencyCallbackModeExitDialog.this.setResult(RESULT_CANCELED);
         finish();
     }
 
@@ -321,8 +316,7 @@
                         mAlertDialog.dismiss();
                     if (mProgressDialog != null)
                         mProgressDialog.dismiss();
-                    EmergencyCallbackModeExitDialog.this.setResult(RESULT_OK, (new Intent())
-                            .putExtra(EXTRA_EXIT_ECM_RESULT, true));
+                    EmergencyCallbackModeExitDialog.this.setResult(RESULT_OK);
                     finish();
                 }
             }
@@ -354,8 +348,7 @@
             switch (msg.what) {
                 case ECM_TIMER_RESET:
                     if(!((Boolean)((AsyncResult) msg.obj).result).booleanValue()) {
-                        EmergencyCallbackModeExitDialog.this.setResult(RESULT_OK, (new Intent())
-                                .putExtra(EXTRA_EXIT_ECM_RESULT, false));
+                        EmergencyCallbackModeExitDialog.this.setResult(RESULT_CANCELED);
                         finish();
                     }
                     break;