Extract magnification capabilities from MagnificationSettingsFragment into a new class.

* To increase single responsibility of MagnificationSettingsFragment

Bug: 168567356
Test: atest MagnificationCapabilitiesTest
Change-Id: Ic5e8a556858ac2b6ab9929b1bbdc373ce320c270

src/com/android/settings/accessibility/MagnificationModePreferenceController.java

@@ -35,7 +35,7 @@ public class MagnificationModePreferenceController extends BasePreferenceControl
 
     @Override
     public CharSequence getSummary() {
-        return MagnificationSettingsFragment.getMagnificationCapabilitiesSummary(
-                mContext);
+        final int capabilities = MagnificationCapabilities.getCapabilities(mContext);
+        return MagnificationCapabilities.getSummary(mContext, capabilities);
     }
 }