Added in fixes and defensive coding for the most frequent crashes

Fixed a crash which could occur when dealing will calls in the background on Android 12 and newer
Fixed a crash when we don't have permission to check the current call state
Fixed a crash when the ScreenshotObserver receives an invalid Uri (just prevent the specific case)

app/src/main/java/org/thoughtcrime/securesms/attachments/ScreenshotObserver.kt

@@ -13,6 +13,11 @@ class ScreenshotObserver(private val context: Context, handler: Handler, private
     override fun onChange(selfChange: Boolean, uri: Uri?) {
         super.onChange(selfChange, uri)
         uri ?: return
+
+        // There is an odd bug where we can get notified for changes to 'content://media/external'
+        // directly which is a protected folder, this code is to prevent that crash
+        if (uri.scheme == "content" && uri.host == "media" && uri.path == "/external") { return }
+
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
             queryRelativeDataColumn(uri)
         } else {

app/src/main/java/org/thoughtcrime/securesms/webrtc/CallManager.kt

@@ -1,7 +1,9 @@
 package org.thoughtcrime.securesms.webrtc
 
 import android.content.Context
+import android.content.pm.PackageManager
 import android.telephony.TelephonyManager
+import androidx.core.content.ContextCompat
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.asSharedFlow
 import kotlinx.serialization.json.Json
@@ -176,8 +178,22 @@ class CallManager(context: Context, audioManager: AudioManagerCompat, private va
         _callStateEvents.value = newState
     }
 
-    fun isBusy(context: Context, callId: UUID) = callId != this.callId && (currentConnectionState != CallState.Idle
-            || context.getSystemService(TelephonyManager::class.java).callState  != TelephonyManager.CALL_STATE_IDLE)
+    fun isBusy(context: Context, callId: UUID): Boolean {
+        // Make sure we have the permission before accessing the callState
+        if (ContextCompat.checkSelfPermission(context, android.Manifest.permission.READ_PHONE_STATE) == PackageManager.PERMISSION_GRANTED) {
+            return (
+                callId != this.callId && (
+                    currentConnectionState != CallState.Idle ||
+                    context.getSystemService(TelephonyManager::class.java).callState != TelephonyManager.CALL_STATE_IDLE
+                )
+            )
+        }
+
+        return (
+            callId != this.callId &&
+            currentConnectionState != CallState.Idle
+        )
+    }
 
     fun isPreOffer() = currentConnectionState == CallState.RemotePreOffer
 

app/src/main/java/org/thoughtcrime/securesms/webrtc/CallMessageProcessor.kt

@@ -78,7 +78,7 @@ class CallMessageProcessor(private val context: Context, private val textSecureP
     private fun incomingHangup(callMessage: CallMessage) {
         val callId = callMessage.callId ?: return
         val hangupIntent = WebRtcCallService.remoteHangupIntent(context, callId)
-        ContextCompat.startForegroundService(context, hangupIntent)
+        context.startService(hangupIntent)
     }
 
     private fun incomingAnswer(callMessage: CallMessage) {
@@ -91,7 +91,7 @@ class CallMessageProcessor(private val context: Context, private val textSecureP
                 sdp = sdp,
                 callId = callId
         )
-        ContextCompat.startForegroundService(context, answerIntent)
+        context.startService(answerIntent)
     }
 
     private fun handleIceCandidates(callMessage: CallMessage) {
@@ -120,7 +120,7 @@ class CallMessageProcessor(private val context: Context, private val textSecureP
                 callId = callId,
                 callTime = callMessage.sentTimestamp!!
         )
-        ContextCompat.startForegroundService(context, incomingIntent)
+        context.startService(incomingIntent)
     }
 
     private fun incomingCall(callMessage: CallMessage) {
@@ -134,8 +134,7 @@ class CallMessageProcessor(private val context: Context, private val textSecureP
                 callId = callId,
                 callTime = callMessage.sentTimestamp!!
         )
-        ContextCompat.startForegroundService(context, incomingIntent)
-
+        context.startService(incomingIntent)
     }
 
     private fun CallMessage.iceCandidates(): List<IceCandidate> {