SettingLib: Add deep sleep info to uptime preference

Add deep sleep ratio to "About Phone" -> "Uptime"
original from Stefan

**DU Edits**
- Simplify the code used to show Deep sleep

Change-Id: I6949a66bae077b5132304448a7c8d7130665437a

Author: maxwen

packages/SettingsLib/res/values/cr_strings.xml

@@ -22,4 +22,5 @@
     <!-- Description for the screen zoom level that makes interface elements smallest. [CHAR LIMIT=24] -->
     <string name="screen_zoom_summary_smallest">Smallest</string>
 
+    <string name="status_deep_sleep">(Deep sleep: %1$d%2$s)</string>
 </resources>

packages/SettingsLib/src/com/android/settingslib/deviceinfo/AbstractUptimePreferenceController.java

@@ -26,6 +26,7 @@
 import androidx.preference.Preference;
 import androidx.preference.PreferenceScreen;
 
+import com.android.settingslib.R;
 import com.android.settingslib.core.AbstractPreferenceController;
 import com.android.settingslib.core.lifecycle.Lifecycle;
 import com.android.settingslib.core.lifecycle.LifecycleObserver;
@@ -89,7 +90,14 @@ private Handler getHandler() {
     }
 
     private void updateTimes() {
-        mUptime.setSummary(DateUtils.formatElapsedTime(SystemClock.elapsedRealtime() / 1000));
+        float deepSleepRatio = Math.max((float) (SystemClock.elapsedRealtime() - SystemClock.uptimeMillis()), 0f)
+                / SystemClock.elapsedRealtime();
+        int deepSleepPercent = Math.round(deepSleepRatio * 100);
+
+        String summary = DateUtils.formatElapsedTime(SystemClock.elapsedRealtime() / 1000) +
+                " " + mContext.getString(R.string.status_deep_sleep, deepSleepPercent, "%");
+
+        mUptime.setSummary(summary.toString());
     }
 
     private static class MyHandler extends Handler {