Refactor to replace FloatPoint by vec2

Using FloatPoint requires unnecessory conversion between vec2 and
FloatPoint, which is inefficient.
This CL replaces FloatPoint by vec2 everywhere.

Test: atest inputflinger_tests
Bug: 245989146
Flag: EXEMPT refactor
Change-Id: I0bf9cd35392bff424ec65bbaa43918176d31de37
5 files changed