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
diff --git a/libs/input/PointerController.h b/libs/input/PointerController.h
index 8b33190..afd7215 100644
--- a/libs/input/PointerController.h
+++ b/libs/input/PointerController.h
@@ -51,9 +51,9 @@
 
     ~PointerController() override;
 
-    FloatPoint move(float deltaX, float deltaY) override;
+    vec2 move(float deltaX, float deltaY) override;
     void setPosition(float x, float y) override;
-    FloatPoint getPosition() const override;
+    vec2 getPosition() const override;
     ui::LogicalDisplayId getDisplayId() const override;
     void fade(Transition transition) override;
     void unfade(Transition transition) override;
@@ -166,13 +166,13 @@
 
     ~TouchPointerController() override;
 
-    FloatPoint move(float, float) override {
+    vec2 move(float, float) override {
         LOG_ALWAYS_FATAL("Should not be called");
     }
     void setPosition(float, float) override {
         LOG_ALWAYS_FATAL("Should not be called");
     }
-    FloatPoint getPosition() const override {
+    vec2 getPosition() const override {
         LOG_ALWAYS_FATAL("Should not be called");
     }
     ui::LogicalDisplayId getDisplayId() const override {