Add RTT call chat window.

This change add a mock in simulator with a type bot that's simulating remote typing. The integration into incall UI will be in following changes.

Bug: 67596257
Test: RttChatMessageTest
PiperOrigin-RevId: 181211591
Change-Id: If6cdcb010afc0c25e90d3a44fe349920d5a856c6
diff --git a/packages.mk b/packages.mk
index 03268fd..d01b3f1 100644
--- a/packages.mk
+++ b/packages.mk
@@ -75,6 +75,7 @@
 	com.android.incallui.hold \
 	com.android.incallui.incall.impl \
 	com.android.incallui.maps.impl \
+	com.android.incallui.rtt.impl \
 	com.android.incallui.sessiondata \
 	com.android.incallui.spam \
 	com.android.incallui.speakerbuttonlogic \