Stop calling IMM#isActive() from TextView#onDraw()

Despite its name, InputMethodManager#isActive(View) internally aquires
IMM lock three times and may even trigger IME focus switching.

To make things simpler and more predictable,

  InputMethodManager#hasActiveInputConnectionInternal(View)

should be used instead, especially for methods like TextView#onDraw().

Bug: 291826769
Test: presubmit
Test: atest CtsInputMethodTestCases
Change-Id: I27f2d66050588c5adc6315160e54486131f3fca2