Convert terminal test to kotlin

and change visibility of class and method which is used for testing

Bug: 387266878
Test: atest TerminalAppTest
Change-Id: I1ceace5aa7a272d7399a571a27c4d5cb909ed435
diff --git a/tests/Terminal/Android.bp b/tests/Terminal/Android.bp
index 029fbea..a4e1f6b 100644
--- a/tests/Terminal/Android.bp
+++ b/tests/Terminal/Android.bp
@@ -4,7 +4,7 @@
 
 android_test {
     name: "TerminalAppTests",
-    srcs: ["src/**/*.java"],
+    srcs: ["src/**/*.kt"],
     libs: [
         "android.test.runner.stubs.system",
         "android.test.base.stubs.system",