Fix GAR issue for battery chart description and the contrast ratio

Bug: 187813918
Bug: 187811403
Test: make SettingsRoboTests
Change-Id: I4fae623a305fd1ee022336bcae35d9dd9995146d

res/layout/battery_chart_graph.xml

@@ -28,7 +28,7 @@
         android:layout_height="wrap_content"
         android:layout_marginVertical="16dp"
         android:textAppearance="?android:attr/textAppearanceSmall"
-        settings:textColor="?android:attr/textColorSecondary"
+        android:textColor="?android:attr/textColorSecondary"
         android:text="@string/battery_usage_chart_graph_hint" />
 
     <com.android.settings.fuelgauge.BatteryChartView
@@ -37,6 +37,7 @@
         android:layout_height="165dp"
         android:layout_marginBottom="16dp"
         android:visibility="invisible"
+        android:contentDescription="@string/battery_usage_chart"
         android:textAppearance="?android:attr/textAppearanceSmall"
         settings:textColor="?android:attr/textColorSecondary" />
     <TextView

res/values/arrays.xml

@@ -1523,7 +1523,6 @@
         [CHAR LIMIT=NONE] -->
     <string-array name="allowlist_hide_entry_in_battery_usage" translatable="false">
         <item>"com.google.android.gms.persistent"</item>
-        <item>"dex2oat64"</item>
     </string-array>
 
     <!-- Array of titles palette list for accessibility. -->

res/values/strings.xml

@@ -6471,6 +6471,8 @@
     <string name="battery_usage_for_background_time">Background: <xliff:g id="time">%s</xliff:g></string>
     <!-- [CHAR_LIMIT=NONE] Battery usage main screen footer contentt -->
     <string name="battery_usage_screen_footer">Battery usage data is approximate and doesn\'t measure usage when phone is charging</string>
+    <!-- [CHAR_LIMIT=NONE] Accessibility content description for battery chart view. -->
+    <string name="battery_usage_chart">Battery usage chart</string>
     <!-- Process Stats strings -->
     <skip />
 

tests/robotests/src/com/android/settings/fuelgauge/BatteryChartPreferenceControllerTest.java

@@ -634,9 +634,6 @@ public final class BatteryChartPreferenceControllerTest {
         assertThat(mBatteryChartPreferenceController
                 .isValidToShowEntry("com.google.android.gms.persistent"))
             .isFalse();
-        assertThat(mBatteryChartPreferenceController
-                .isValidToShowEntry("dex2oat64"))
-            .isFalse();
     }
 
     private static Map<Long, Map<String, BatteryHistEntry>> createBatteryHistoryMap() {