Fix to avoid lastEnableArguments to be set to null due to cancelOnLeavePiP call

[dev-aman]

What

Fix to avoid lastEnableArguments to be set to null due to cancelOnLeavePiP call

Why

This will avoid the case where pip status is always disabled and not automatic when it should be automatic post pip is enabled but not visible. (with respect to on LeavePIP)

[Copilot]

Pull Request Overview

This PR ensures that lastEnableArguments is set only after cancelOnLeavePiP() completes, preventing it from being cleared by that call.

• Removed the early assignment of lastEnableArguments at the start of enable()
• Added assignment of lastEnableArguments after cancelOnLeavePiP() with a descriptive comment

Comments suppressed due to low confidence (2)

lib/src/floating.dart:144

• [nitpick] Add a unit test to verify that after calling enable(), lastEnableArguments retains the passed arguments and is not reset by cancelOnLeavePiP().

    lastEnableArguments = arguments;

lib/src/floating.dart:142

• [nitpick] The comment could be more concise. For example: "Assign lastEnableArguments after cancelOnLeavePiP() to avoid it being overridden."

    // Moved this here as setting it on the first line does not make sense since