input: replace pointer acceleration factor with a boolean

InputManagerService's setPointerAcceleration method is only ever called
with values of 1 (which disables pointer acceleration completely) or 3
(the default, as specified in IInputConstants.aidl), so it is
effectively being used as a boolean toggle for acceleration. Exposing a
single number to control pointer acceleration only makes sense because
our acceleration "curve" is basically a flat line, of which the number
controls the gradient.

We are about to replace the acceleration curve with a more sophisticated
one, and keeping this numerical factor would make that work more
complicated. Since there is only a use case for disabling acceleration
altogether, replace setPointerAcceleration with
setMousePointerAccelerationEnabled, which takes a boolean.

Since the new touchpad mapper was implemented, the pointer speed and
acceleration for touchpads and mice have been implemented and controlled
separately, so also add "mouse" to the method name to make it clear that
only one type of pointer input is affected by the setting.

Bug: 315313622
Test: atest InputTests
Test: atest FrameworksServicesTests:com.android.server.companion.virtual.VirtualDeviceManagerServiceTest
Test: atest VirtualMouseTest
Test: atest VirtualDeviceMirrorDisplayTest
Change-Id: I88dba6788c51644e7a4672cceca4e0338cde0168