Added update feature

app/src/main/AndroidManifest.xml

@@ -3,6 +3,8 @@
     package="xyz.quaver.pupil">
 
     <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
+    <uses-permission android:name="android.permission.REQUEST_INSTALL_PACKAGES"/>
 
     <application
         android:allowBackup="true"
@@ -12,6 +14,17 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/AppTheme">
+
+        <provider
+            android:name="androidx.core.content.FileProvider"
+            android:authorities="xyz.quaver.pupil.provider"
+            android:exported="false"
+            android:grantUriPermissions="true">
+            <meta-data
+                android:name="android.support.FILE_PROVIDER_PATHS"
+                android:resource="@xml/filepaths"/>
+        </provider>
+
         <activity android:name=".GalleryActivity"
                   android:configChanges="keyboardHidden|orientation|screenSize"/>
         <activity