Fix battery content description when there is no percent mode

Fixes: 135157243
Test: can focus on status bar battery when talkback is on
Change-Id: I413ba6664bc651ddc378ae344fa42a17d460bfa5

packages/SystemUI/src/com/android/systemui/BatteryMeterView.java

@@ -365,6 +365,10 @@ public class BatteryMeterView extends LinearLayout implements
             } else {
                 setPercentTextAtCurrentLevel();
             }
+        } else {
+            setContentDescription(
+                    getContext().getString(mCharging ? R.string.accessibility_battery_level_charging
+                            : R.string.accessibility_battery_level, mLevel));
         }
     }