Fix to open conversation list when navigating back after chat was opened by notification

Signed-off-by: Marcel Hibbe <dev@mhibbe.de>

app/src/main/AndroidManifest.xml

@@ -222,6 +222,7 @@
             android:name=".chat.ChatActivity"
             android:theme="@style/AppTheme"
             android:launchMode="singleInstance"
+            android:noHistory="true"
             android:screenOrientation="portrait" />
 
         <activity

app/src/main/java/com/nextcloud/talk/chat/ChatActivity.kt

@@ -579,6 +579,12 @@ class ChatActivity :
         viewThemeUtils.material.themeToolbar(binding.chatToolbar)
     }
 
+    override fun onBackPressed() {
+        val intent = Intent(this, ConversationsListActivity::class.java)
+        intent.putExtras(Bundle())
+        startActivity(intent)
+    }
+
     private fun initAdapter() {
         val senderId = if (!conversationUser!!.userId.equals("?")) {
             "users/" + conversationUser!!.userId