[input][e2e] Re-enable input e2e test.

Flake did not repro in qsr's setup, so I'm tentatively calling it good.

Please re-open the issue if CQ runs still turn out flaky!

SCN-1446 #done

TEST=CQ

Change-Id: I5647b737cfc38db4ed97c0d7dbf4302985614d6b
diff --git a/garnet/tests/e2e_input_tests/minimal_input_test.cc b/garnet/tests/e2e_input_tests/minimal_input_test.cc
index d65ae47..e6a0e46 100644
--- a/garnet/tests/e2e_input_tests/minimal_input_test.cc
+++ b/garnet/tests/e2e_input_tests/minimal_input_test.cc
@@ -218,7 +218,7 @@
   bool test_was_run_ = false;
 };
 
-TEST_F(MinimalInputTest, DISABLED_Tap) {
+TEST_F(MinimalInputTest, Tap) {
   // Set up inputs. Fires when display and content are available.
   SetInjectInputCallback([this] {
     InjectInput({"tap",  // Tap at the center of the display