Follow revert back to oc-dev APIs.

Test: builds, boots
Bug: 62431162
Change-Id: Ibee5f29da756b6922109b95c36fd340f02e1905e
diff --git a/testapps/src/com/android/server/telecom/testapps/TestRttActivity.java b/testapps/src/com/android/server/telecom/testapps/TestRttActivity.java
index b78a48a..9bb6977 100644
--- a/testapps/src/com/android/server/telecom/testapps/TestRttActivity.java
+++ b/testapps/src/com/android/server/telecom/testapps/TestRttActivity.java
@@ -93,12 +93,7 @@
                     }
                     // inner read loop
                     while (true) {
-                        String receivedText;
-                        try {
-                            receivedText = rttCall.read();
-                        } catch (IOException e) {
-                            break;
-                        }
+                        String receivedText = rttCall.read();
                         if (receivedText == null) {
                             if (Thread.currentThread().isInterrupted()) {
                                 break begin;