allow the app be ran over lockscreen

app/src/main/AndroidManifest.xml

@@ -14,6 +14,7 @@
 
     <uses-permission android:name="android.permission.RECORD_AUDIO"/>
     <uses-permission android:name="android.permission.CAMERA"/>
+    <uses-permission android:name="android.permission.DISABLE_KEYGUARD"/>
     <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
     <uses-permission
         android:name="android.permission.USE_FINGERPRINT"
@@ -40,6 +41,7 @@
         <activity
             android:name=".activities.MainActivity"
             android:screenOrientation="portrait"
+            android:showOnLockScreen="true"
             android:theme="@style/FullScreenTheme">
 
             <intent-filter>

app/src/main/kotlin/com/simplemobiletools/camera/activities/MainActivity.kt

@@ -51,6 +51,11 @@ class MainActivity : SimpleActivity(), PreviewListener, PhotoProcessor.MediaSave
     lateinit var mOrientationEventListener: OrientationEventListener
 
     override fun onCreate(savedInstanceState: Bundle?) {
+        window.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON or
+                WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD or
+                WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED or
+                WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON)
+
         useDynamicTheme = false
         super.onCreate(savedInstanceState)
         appLaunched()

app/src/main/kotlin/com/simplemobiletools/camera/receivers/HardwareShutterReceiver.kt

@@ -3,7 +3,6 @@ package com.simplemobiletools.camera.receivers
 import android.content.BroadcastReceiver
 import android.content.Context
 import android.content.Intent
-
 import com.simplemobiletools.camera.activities.MainActivity
 
 class HardwareShutterReceiver : BroadcastReceiver() {