Fix android build errors with RN 0.71

- Add redundant handling for missing permission exceptions. Existing checks work but do not satisfy lint, so this is the only way to resolve react-native-webrtc#646.

- Upgrade gradle to maximum compatible version (3.6.4) to satisfy new minimum (3.2.0).

- Replace use of deprecated API methods and constants.

- Increase android minSdk version to 27 (to use Activity.setShowWhenLocked/setTurnScreenOn).

android/build.gradle

@@ -5,7 +5,7 @@ buildscript {
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.0.1'
+        classpath 'com.android.tools.build:gradle:3.6.4'
     }
 }
 
@@ -19,7 +19,7 @@ android {
     compileSdkVersion safeExtGet('compileSdkVersion', 28)
 
     defaultConfig {
-        minSdkVersion safeExtGet('minSdkVersion', 23)
+        minSdkVersion safeExtGet('minSdkVersion', 27)
         targetSdkVersion safeExtGet('targetSdkVersion', 28)
         versionCode 1
         versionName "1.0"

android/src/main/java/io/wazo/callkeep/RNCallKeepModule.java

@@ -376,7 +376,9 @@ public void startCall(String uuid, String number, String callerName, boolean has
 
         Log.d(TAG, "[RNCallKeepModule] startCall, uuid: " + uuid);
 
-        telecomManager.placeCall(uri, extras);
+        try {
+            telecomManager.placeCall(uri, extras);
+        } catch (SecurityException ignored) {}
     }
 
     @ReactMethod
@@ -394,7 +396,7 @@ public void endCall(String uuid) {
         }
         Context context = this.getAppContext();
         AudioManager audioManager = (AudioManager) context.getSystemService(context.AUDIO_SERVICE);
-        audioManager.setMode(0);
+        audioManager.setMode(AudioManager.MODE_NORMAL);
         conn.onDisconnect();
 
         Log.d(TAG, "[RNCallKeepModule] endCall executed, uuid: " + uuid);
@@ -535,7 +537,11 @@ public void checkDefaultPhoneAccount(Promise promise) {
         }
 
         boolean hasSim = telephonyManager.getSimState() != TelephonyManager.SIM_STATE_ABSENT;
-        boolean hasDefaultAccount = telecomManager.getDefaultOutgoingPhoneAccount("tel") != null;
+
+        boolean hasDefaultAccount = false;
+        try {
+            hasDefaultAccount = telecomManager.getDefaultOutgoingPhoneAccount("tel") != null;
+        } catch (SecurityException ignored) {}
 
         promise.resolve(!hasSim || hasDefaultAccount);
     }
@@ -910,11 +916,9 @@ public void backToForeground() {
             focusIntent.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
             activity.startActivity(focusIntent);
         } else {
-            focusIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK +
-                    WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED +
-                    WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD +
-                    WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON);
-
+            focusIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+            activity.setShowWhenLocked(true);
+            activity.setTurnScreenOn(true);
             getReactApplicationContext().startActivity(focusIntent);
         }
     }

android/src/main/java/io/wazo/callkeep/VoiceConnectionService.java

@@ -25,6 +25,7 @@
 import android.app.NotificationManager;
 import android.app.PendingIntent;
 import android.app.Activity;
+import android.app.Service;
 import android.content.res.Resources;
 import android.content.Intent;
 import android.content.Context;
@@ -353,7 +354,7 @@ private void stopForegroundService() {
         }
 
         try {
-            stopForeground(FOREGROUND_SERVICE_TYPE_MICROPHONE);
+            stopForeground(Service.STOP_FOREGROUND_REMOVE);
         } catch (Exception e) {
             Log.w(TAG, "[VoiceConnectionService] can't stop foreground service :" + e.toString());
         }