Extract Gesture handling code and test it

Similarly to the HardwareState logic, extracting this code makes things
a bit clearer and easier to test.

Bug: 251196347
Test: m inputflinger_tests && \
    $ANDROID_HOST_OUT/nativetest64/inputflinger_tests/inputflinger_tests \
    --gtest_filter='*HardwareStateConverterTest*'
Test: atest inputflinger_tests
Change-Id: I6902e052fc5e193228aca4378587413b22889b26
diff --git a/services/inputflinger/tests/Android.bp b/services/inputflinger/tests/Android.bp
index 547a488..58a5c31 100644
--- a/services/inputflinger/tests/Android.bp
+++ b/services/inputflinger/tests/Android.bp
@@ -44,6 +44,7 @@
         "FakeInputReaderPolicy.cpp",
         "FakePointerController.cpp",
         "FocusResolver_test.cpp",
+        "GestureConverter_test.cpp",
         "HardwareStateConverter_test.cpp",
         "InputMapperTest.cpp",
         "InputProcessor_test.cpp",