Use separate x and y DPI for mice move scaling

Use the xDpi and yDpi values from the DisplayViewport in the
CursorInputMapper to scale mice moves.

Test: inputflinger_tests
Test: manual
Bug: 432649760
Flag: com.android.input.flags.use_separate_xy_dpi_scaling_for_mice
Change-Id: I8a7803fe024745bbf27f7102bc46db4a208fd57b