Add left/ right scrolling for mouse keys

Earlier we could only scroll up and down if the scroll toggle was on
for mouse keys. This CL adds the ability to scroll left and right
when the scroll toggle is on.

Bug: 341799888
Test: atest FrameworksServicesTests:MouseKeysInterceptorTest
Flag: EXEMPT bugfix
Change-Id: I75025a39bc9a67015664475e0f2abaeb9e026d8f