Add a flag for the Bluetooth device details page

This flag will be used to control whether we use a new, separate page
for Bluetooth device details, or the existing dialog.

Bug: 35877479
Test: make RunSettingsGoogleRoboTests
Change-Id: I2bda77493695ebe3b3bb824657a1422a68918256

src/com/android/settings/bluetooth/BluetoothFeatureProvider.java

@@ -21,7 +21,12 @@ package com.android.settings.bluetooth;
  */
 public interface BluetoothFeatureProvider {
     /**
-     * Check whether additional pairing page is enabled
+     * @return whether additional pairing page is enabled
      */
     boolean isPairingPageEnabled();
+
+    /**
+     * @return whether device details should be shown as a separate page (true) or a dialog (false)
+     */
+    boolean isDeviceDetailPageEnabled();
 }