Fix Overdraw warning for EditImageActivity

Signed-off-by: ZetaTom <70907959+ZetaTom@users.noreply.github.com>

app/src/main/AndroidManifest.xml

@@ -490,7 +490,7 @@
         <activity
             android:name="com.nextcloud.client.editimage.EditImageActivity"
             android:exported="false"
-            android:theme="@style/Theme.ownCloud.Toolbar" />
+            android:theme="@style/Theme.ownCloud.Toolbar.NullBackground" />
 
         <activity
             android:name="com.nmc.android.ui.LauncherActivity"

app/src/main/res/values/styles.xml

@@ -140,6 +140,11 @@
         <item name="android:navigationBarColor">@color/bg_default</item>
     </style>
 
+    <style name="Theme.ownCloud.Toolbar.NullBackground" parent="BaseTheme.ownCloud.Toolbar">
+        <item name="android:colorBackground">@null</item>
+        <item name="android:background">@null</item>
+    </style>
+
     <style name="Theme.ownCloud.noActionBar.LoginBase" parent="Theme.ownCloud.Toolbar">
         <item name="android:windowBackground">@color/primary</item>
         <item name="colorControlNormal">@color/login_text_color</item>