We are currently developing an app where we'd like to change some system settings, with user permission of course. The android documentation says that to do this, you have to add the following permission:
<uses-permission android:name="android.permission.WRITE_SETTINGS" />
Also, one has to explicitly ask the user to enable this permission. An excerpt from https://developer.android.com/reference/android/Manifest.permission#WRITE_SETTINGS says:
Note: If the app targets API level 23 or higher, the app user must explicitly grant this permission to the app through a permission management screen. The app requests the user's approval by sending an intent with action
Settings.ACTION_MANAGE_WRITE_SETTINGS. The app can check whether it has this authorization by callingSettings.System.canWrite().
Up until this point, it is quite clear. However, when the permission is added to the AndroidManifest.xml file, Android Studio complains that "Permission is only granted to system apps". Now, this is confusing since I haven't found any documentation stating that it is indeed only granted to system apps.
So, I'd like to ask if someone has encountered this issue, and if there is some kind of documentation that explains this in detail? Or am I simply missing something?
As stated by user passsy in the stackoverflow question provided by Brian, android.permission.WRITE_SETTINGS has a android:protectionLevel of "signature", which makes the permission unavailable for use in user applications since API level 23.
See https://developer.android.com/guide/topics/manifest/permission-element#plevel for the description of protection levels for permissions.