Follow footer preference guildance on some pages

- Footer preference should have a info icon in tethering page.
- Rmove an empty icon for screen attention setting.
- Revise the "More details" to "Learn more"
- Add more empty line between footer info and "Learn more"

Test: Built apk, and check the screen
Fix: 183472971
Fix: 183472858
Change-Id: I7edb71639b59efb8205c0ef6a50ab483f88aa63d

res/values/strings.xml

@@ -6612,7 +6612,7 @@
 
     <!-- Message displayed to let the user know that some of the options are disabled by admin. [CHAR LIMIT=NONE] -->
     <string name="admin_disabled_other_options">Other options are disabled by your admin</string>
-    <string name="admin_more_details">More details</string>
+    <string name="admin_more_details">Learn more</string>
     <string name="notification_log_title">Notification log</string>
 
     <string name="notification_history_title">Notification history</string>

res/xml/tether_prefs.xml

@@ -49,9 +49,9 @@
         android:summary="@string/ethernet_tethering_subtext"
         settings:keywords="@string/keywords_hotspot_tethering" />
 
-    <Preference
+    <com.android.settingslib.widget.FooterPreference
         android:key="disabled_on_data_saver"
-        android:summary="@string/tether_settings_disabled_on_data_saver"
+        android:title="@string/tether_settings_disabled_on_data_saver"
         android:selectable="false"
-        settings:allowDividerAbove="true" />
+        settings:searchable="false"/>
 </PreferenceScreen>

src/com/android/settings/display/AdaptiveSleepPreferenceController.java

@@ -60,7 +60,6 @@ public class AdaptiveSleepPreferenceController {
         mPreference = new RestrictedSwitchPreference(context);
         mPreference.setTitle(R.string.adaptive_sleep_title);
         mPreference.setSummary(R.string.adaptive_sleep_description);
-        mPreference.setIcon(R.drawable.empty_icon);
         mPreference.setChecked(isChecked());
         mPreference.setKey(PREFERENCE_KEY);
         mPreference.setOnPreferenceClickListener(preference -> {

src/com/android/settings/display/ScreenTimeoutSettings.java

@@ -164,7 +164,8 @@ public class ScreenTimeoutSettings extends RadioButtonPickerFragment implements
         final String textMoreDetails = getResources().getString(R.string.admin_more_details);
 
         final SpannableString spannableString = new SpannableString(
-                textDisabledByAdmin + System.lineSeparator() + textMoreDetails);
+                textDisabledByAdmin + System.lineSeparator()
+                + System.lineSeparator() + textMoreDetails);
         final ClickableSpan clickableSpan = new ClickableSpan() {
             @Override
             public void onClick(@NonNull View widget) {
@@ -174,7 +175,7 @@ public class ScreenTimeoutSettings extends RadioButtonPickerFragment implements
 
         if (textDisabledByAdmin != null && textMoreDetails != null) {
             spannableString.setSpan(clickableSpan, textDisabledByAdmin.length() + 1,
-                    textDisabledByAdmin.length() + textMoreDetails.length() + 1,
+                    textDisabledByAdmin.length() + textMoreDetails.length() + 2,
                     Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
         }