Add event ID generator.

Bug: 144889238
Test: atest libinput_test
Change-Id: I0fd192b3c5a08326aa6a6598025c7b8cdc64cce4
diff --git a/libs/input/tests/Android.bp b/libs/input/tests/Android.bp
index fb21d5e..3b57146 100644
--- a/libs/input/tests/Android.bp
+++ b/libs/input/tests/Android.bp
@@ -2,6 +2,7 @@
 cc_test {
     name: "libinput_tests",
     srcs: [
+        "IdGenerator_test.cpp",
         "InputChannel_test.cpp",
         "InputDevice_test.cpp",
         "InputEvent_test.cpp",