Implement draggability feature for TouchpadDebugView

Added a draggability feature to TouchpadDebugView, allowing users to
reposition the view by touch. Constrained the view's movement to stay
within the screen boundaries, preventing it from being dragged
off-screen. Handled screen rotation events by adjusting the view's
position to remain within the new screen dimensions after rotation.

Bug: 359897456
Bug: 360137357

Test: atest TouchpadDebugViewTest
Test: Added unit tests to cover scenarios such as dragging the view,
ensuring the view stays within screen bounds, verifying no movement
for minimal touch input, and confirming the view returns to its
original position when the action is canceled. Manual testing was
also performed to validate these behaviors.
flag: com.android.hardware.input.touchpad_visualizer

Change-Id: I636a01e0741e32154ccee575e178f2aa38e44a0a