add activity to handle system Qr tile intent

Author: empratyush

app/src/main/AndroidManifest.xml

@@ -188,6 +188,11 @@
             android:showWhenLocked="true"
             android:exported="false"/>
 
+        <activity
+            android:name=".ui.activities.QrTile"
+            android:exported="true"
+            android:excludeFromRecents="true"/>
+
     </application>
 
 </manifest>

app/src/main/java/app/grapheneos/camera/CamConfig.kt

@@ -42,6 +42,7 @@ import app.grapheneos.camera.ktx.markAs4by3Layout
 import app.grapheneos.camera.ui.activities.CaptureActivity
 import app.grapheneos.camera.ui.activities.MainActivity
 import app.grapheneos.camera.ui.activities.MoreSettings
+import app.grapheneos.camera.ui.activities.QrTile
 import app.grapheneos.camera.ui.activities.SecureActivity
 import app.grapheneos.camera.ui.activities.SecureMainActivity
 import app.grapheneos.camera.ui.activities.VideoCaptureActivity
@@ -271,6 +272,7 @@ class CamConfig(private val mActivity: MainActivity) {
             }
         }
 
+    private val defaultMode =  if (mActivity is QrTile) CameraMode.QR_SCAN else DEFAULT_CAMERA_MODE
     private var currentMode: CameraMode = DEFAULT_CAMERA_MODE
 
     var aspectRatio: Int
@@ -1272,7 +1274,7 @@ class CamConfig(private val mActivity: MainActivity) {
                 }
                 tab.tag = mode
 
-                tabLayout.addTab(tab, mode == DEFAULT_CAMERA_MODE)
+                tabLayout.addTab(tab, mode == defaultMode)
             }
         }
     }

app/src/main/java/app/grapheneos/camera/ui/activities/QrTile.kt

@@ -0,0 +1,12 @@
+package app.grapheneos.camera.ui.activities
+
+import android.os.Bundle
+import app.grapheneos.camera.CameraMode
+
+class QrTile : MainActivity() {
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        camConfig.switchMode(CameraMode.QR_SCAN)
+    }
+}