Add more information text into RTT settings.

Screenshot:
https://screenshot.googleplex.com/OzfEvLJvsNc

Bug: 76156715
Test: local build
Change-Id: I6068fcf677e1b0d266b8b5102c9b4609572391c6
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 891a45b..3ad24d8 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -1187,10 +1187,10 @@
     <string name="rtt_mode_summary">Allow messaging within a voice call</string>
     <string name="rtt_mode_more_information">
        RTT assists callers who are deaf, hard hearing, have a speech disability,
-       or need more than voice alone.<br/>
+       or need more than voice alone.&lt;br>
        &lt;a href="<xliff:g example="http://www.google.com" id="url">http://support.google.com/mobile?p=telephony_rtt</xliff:g>">Learn more&lt;/a>
-       <br/> - RTT calls are saved as a message transcript
-       <br/> - RTT is not available for video calls</string>
+       &lt;br>&lt;br> - RTT calls are saved as a message transcript
+       &lt;br> - RTT is not available for video calls</string>
 
     <!-- Service option entries.  -->
     <string-array name="tty_mode_entries">