Disable bluetooth controller if unsupported

Only disable the controllers not the whole fragment because
user might need to have entry for other features.

Fixes: 73664409
Merged-In: I98ed248cf33d11715dd523e711cbc68ebf128ef8
Change-Id: I98ed248cf33d11715dd523e711cbc68ebf128ef8
Signed-off-by: Weilun Du <wdu@google.com>
(cherry picked from commit 68a195ae93)

tests/robotests/src/com/android/settings/bluetooth/BluetoothFilesPreferenceControllerTest.java

@@ -18,6 +18,10 @@ package com.android.settings.bluetooth;
 
 import static com.google.common.truth.Truth.assertThat;
 
+import static org.mockito.Mockito.doReturn;
+import static org.mockito.Mockito.spy;
+
+import android.content.pm.PackageManager;
 import android.content.Context;
 import android.content.Intent;
 import android.os.Bundle;
@@ -28,6 +32,7 @@ import com.android.settings.testutils.SettingsRobolectricTestRunner;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 import org.robolectric.RuntimeEnvironment;
 import org.robolectric.shadows.ShadowApplication;
@@ -38,15 +43,18 @@ public class BluetoothFilesPreferenceControllerTest {
     private Context mContext;
     private BluetoothFilesPreferenceController mController;
     private Preference mPreference;
+    @Mock
+    private PackageManager mPackageManager;
 
     @Before
     public void setUp() {
         MockitoAnnotations.initMocks(this);
-
-        mContext = RuntimeEnvironment.application;
+        mContext = spy(RuntimeEnvironment.application);
         mController = new BluetoothFilesPreferenceController(mContext);
         mPreference = new Preference(mContext);
         mPreference.setKey(BluetoothFilesPreferenceController.KEY_RECEIVED_FILES);
+        doReturn(mPackageManager).when(mContext).getPackageManager();
+        doReturn(true).when(mPackageManager).hasSystemFeature(PackageManager.FEATURE_BLUETOOTH);
     }
 
     @Test