Add small clock option description

Test: See screenshot in bug
Bug: 269567954
Change-Id: I5d0b426be06a7404dc4963c4bae3842498ee26b9
diff --git a/res/layout/clock_size_radio_button_group.xml b/res/layout/clock_size_radio_button_group.xml
index 2aa78d2..56d0ab7 100644
--- a/res/layout/clock_size_radio_button_group.xml
+++ b/res/layout/clock_size_radio_button_group.xml
@@ -68,11 +68,21 @@
             android:layout_marginEnd="8dp"
             android:clickable="false" />
 
-        <TextView
-            style="@style/SectionTitleTextStyle"
-            android:layout_width="wrap_content"
+        <LinearLayout
+            android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:layout_gravity="center_vertical"
-            android:text="@string/clock_size_small" />
+            android:orientation="vertical">
+            <TextView
+                style="@style/SectionTitleTextStyle"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/clock_size_small" />
+
+            <TextView
+                style="@style/SectionSubtitleTextStyle"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="@string/clock_size_small_description" />
+        </LinearLayout>
     </LinearLayout>
 </LinearLayout>
\ No newline at end of file
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 680947d..eb68dce 100755
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -90,6 +90,9 @@
     <!-- Title of a radio button to apply clock size small. [CHAR LIMIT=15] -->
     <string name="clock_size_small">Small</string>
 
+    <!-- Description of a radio button to apply clock size small. [CHAR LIMIT=NONE] -->
+    <string name="clock_size_small_description">A small clock shows in the corner of your screen</string>
+
     <!-- Title of a section of the customization picker where the user can select a Grid size for
         the home screen. [CHAR LIMIT=15] -->
     <string name="grid_title">App grid</string>