When using the up arrow, navigate back to the main messages screen

- Ensures only 1 main activity can be launched

features/home/src/main/AndroidManifest.xml

@@ -2,7 +2,7 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android">
 
     <application>
-        <activity android:name="app.dapk.st.home.MainActivity"/>
+        <activity android:name="app.dapk.st.home.MainActivity" android:launchMode="singleInstance"/>
     </application>
 
 </manifest>

features/navigator/src/main/kotlin/app/dapk/st/navigator/Navigator.kt

@@ -6,6 +6,7 @@ import android.content.Context
 import android.content.Intent
 import android.os.Parcel
 import android.os.Parcelable
+import androidx.core.app.NavUtils
 import app.dapk.st.core.AndroidUri
 import app.dapk.st.core.MimeType
 import app.dapk.st.matrix.common.RoomId
@@ -33,7 +34,8 @@ interface Navigator {
         }
 
         fun upToHome() {
-            activity.navigateUpTo(intentFactory.home(activity))
+            activity.finish()
+            activity.startActivity(intentFactory.home(activity))
         }
 
         fun toMessenger(roomId: RoomId, attachments: List<MessageAttachment>) {