Why READ_PHONE_STATE permission asked "make and manage phone call"?

Question

For getting the IMEI i using from this code:

TelephonyManager tm = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
       if (ActivityCompat.checkSelfPermission(this, Manifest.permission.READ_PHONE_STATE) != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_PHONE_STATE}, 1);
        } else { 
                iMEI = tm.getDeviceId(); 
        }

But when my app is running this dialog box coming up:

The program asks to grant permission To make and manage phone calls which can scary users from using app.

And now my question is:

Why READ_PHONE_STATE permission asked "make and manage phone call"? While I have not make phone call and manage phone call in my app.

Answer 1

READ_PHONE_STATE permission is listed as Dangerous permission and provides access to read phone state. It comes under the Phone permission group. If dangerous permission is asked, the system shows dialog related to its group. in your case, Phone. and That is the reason- the user is asked for "make and manage phone call" permission. This is how the permissions are asked- https://developer.android.com/training/permissions/requesting

To make it more clear, see https://developer.android.com/guide/topics/permissions/overview

It says -

If the device is running Android 6.0 (API level 23) and the app's targetSdkVersion is 23 or higher, the following system behavior applies when your app requests a dangerous permission:

• If the app doesn't currently have any permissions in the permission group, the system shows the permission request dialog to the user
  describing the permission group that the app wants access to. The
  dialog doesn't describe the specific permission within that group.
  For example, if an app requests the READ_CONTACTS permission, the
  system dialog just says the app needs access to the device's
  contacts. If the user grants approval, the system gives the app just
  the permission it requested.

• If the app has already been granted another dangerous permission in the same permission group, the system immediately grants the
  permission without any interaction with the user. For example, if an
  app had previously requested and been granted the READ_CONTACTS
  permission, and it then requests WRITE_CONTACTS, the system
  immediately grants that permission without showing the permissions
  dialog to the user.

There are a lot of better ways to get a unique identifier. For example-

String android_id = Settings.Secure.getString(getApplicationContext().getContentResolver(),
                Settings.Secure.ANDROID_ID);

Answer 2

Why READ_PHONE_STATE permission asked "make and manage phone call"? While I have not make phone call and manage phone call in my app.

After Marshmallow we need to explicitly call the permissions which come under Dangerous permission.

READ_PHONE_STATE comes under Permission Group Called Phone