Heads-up notifications for low battery warnings.

Falls back to dialogs when heads-up are N/A.

Add new ongoing notification if battery saver mode
is active.  Offer to start battery saver on warnings,
if not already started.

True up BatteryMeterView's levels to the latest threshold
levels.  15% for first warning.

Bug:13329308
Change-Id: Id8ad11a1997079ee7165ae003a8fa1c744462ab3
diff --git a/packages/SystemUI/res/values/strings.xml b/packages/SystemUI/res/values/strings.xml
index de297e5..260f59c 100644
--- a/packages/SystemUI/res/values/strings.xml
+++ b/packages/SystemUI/res/values/strings.xml
@@ -59,25 +59,43 @@
     <string name="status_bar_latest_events_title">Notifications</string>
 
     <!-- When the battery is low, this is displayed to the user in a dialog.  The title of the low battery alert.  [CHAR LIMIT=NONE]-->
-    <string name="battery_low_title">Connect charger</string>
-
-    <!-- When the battery is low, this is displayed to the user in a dialog. The subtitle of the low battery alert. [CHAR LIMIT=NONE] -->
-    <string name="battery_low_subtitle">The battery is getting low.</string>
+    <string name="battery_low_title">Battery is low</string>
 
     <!-- A message that appears when the battery level is getting low in a dialog.  This is
         appened to the subtitle of the low battery alert.  "number" is the percentage of battery
         remaining [CHAR LIMIT=none]-->
     <string name="battery_low_percent_format"><xliff:g id="number">%d%%</xliff:g> remaining</string>
 
+    <!-- Same as battery_low_percent_format, with a notice about battery saver if on. [CHAR LIMIT=none]-->
+    <string name="battery_low_percent_format_saver_started"><xliff:g id="number">%d%%</xliff:g> remaining. Battery saver is on.</string>
+
     <!-- A message that appears when a USB charger is plugged in and the device does not
     support charging on it.  That is, a charger that fits into the USB port and goes into
     a wall socket, not into a computer. (This happens because some devices require more
     current than the USB spec allows.  [CHAR LIMIT=NONE] -->
     <string name="invalid_charger">USB charging not supported.\nUse only the supplied charger.</string>
 
+    <!-- First line of invalid_charger, used in the notification form.  [CHAR LIMIT=NONE]-->
+    <string name="invalid_charger_title">USB charging not supported.</string>
+
+    <!-- Second line of invalid_charger, used in the notification form.  [CHAR LIMIT=NONE]-->
+    <string name="invalid_charger_text">Use only the supplied charger.</string>
+
     <!-- When the battery is low, this is the label of the button to go to the
          power usage activity to find out what drained the battery.  [CHAR LIMIT=30] -->
-    <string name="battery_low_why">Battery use</string>
+    <string name="battery_low_why">Settings</string>
+
+    <!-- Battery saver confirmation dialog title [CHAR LIMIT=NONE]-->
+    <string name="battery_saver_confirmation_title">Start battery saver?</string>
+
+    <!-- Battery saver confirmation dialog ok text [CHAR LIMIT=40]-->
+    <string name="battery_saver_confirmation_ok">Start</string>
+
+    <!-- Battery saver notification action [CHAR LIMIT=NONE]-->
+    <string name="battery_saver_start_action">Start battery saver</string>
+
+    <!-- Battery saver confirmation dialog text [CHAR LIMIT=NONE]-->
+    <string name="battery_saver_confirmation_text">To help improve battery life, Battery saver will reduce your device’s performance.\n\nBattery saver will be disabled when your device is plugged in.</string>
 
     <!-- Name of the button that links to the Settings app. [CHAR LIMIT=NONE] -->
     <string name="status_bar_settings_settings_button">Settings</string>
@@ -595,4 +613,13 @@
         <item quantity="one">For one hour</item>
         <item quantity="other">For %d hours</item>
     </plurals>
+
+    <!-- Battery saver notification title. [CHAR LIMIT=60]-->
+    <string name="battery_saver_notification_title">Battery saver is on</string>
+
+    <!-- Battery saver notification text. [CHAR LIMIT=60] -->
+    <string name="battery_saver_notification_text">Device performance is reduced.</string>
+
+    <!-- Battery saver notification action text. [CHAR LIMIT=60] -->
+    <string name="battery_saver_notification_action_text">Open battery saver settings</string>
 </resources>