Fix the following bug:
* Have a moveable ImGui overlay enabled, such as the Statistics window.
* Pause the game.
* Click and hold on the overlay's title bar as if you were going to move
it. Because the screen isn't updating while the game is paused, you
won't be able to actually move the overlay.
* Press the Frame Advance hotkey several times until it stops
responding.
At this point emulation hotkeys are no longer responsive. This can be
resolved by selecting Play from the toolbar or menu, or selecting Frame
Advance from the menu a couple times, but it's annoying and not obvious
what's gone wrong or how to fix it.
Why the bug is happening:
* Doing a framestep while clicking on the overlay title bar causes ImGui
to set IO.WantCaptureKeyboard to true, indicating that ImGui is
requesting Dolphin ignore any keyboard events while the overlay is
being interacted with.
* Dolphin complies with this request, causing
Host_UIBlocksControllerState to return true and thus setting the input
gate to ignore input.
* IO.WantCaptureKeyboard is only updated when ImGui::NewFrame() is
called, which only happens at the end of each present. It thus remains
true indefinitely since the game paused after the last framestep, and
so Dolphin ignores any hotkeys such as the framestep or play keys.
The fix:
Ignore IO.WantCaptureKeyboard when the game is paused. ImGui can't
meaningfully capture input anyway when the game is paused, so this
shouldn't cause any problems elsewhere.
Once async presentation is implemented we'll want to revert this change,
both because it'll become unnecessary and because ImGui will be able to
do stuff while paused and so suppressing emulation hotkeys will actually
be useful.
This is an Android continuation of bc95c00. We now call
InputDetector::Update immediately after receiving an input event from
Android instead of periodically calling it in a sleep loop. This
improves detection of very short inputs, which are especially likely to
occur for volume buttons on phones (or at least on my phone) if you
don't intentionally keep them held down.
bbf72e7 made a change where you can pass `false` to certain MemChecks
functions to get them to skip performing an "update" step. It was then
up to the caller to call the Update function later.
This commit changes the implementation so that, instead of the caller
passing in a boolean that controls whether a function calls Update, the
function now returns an object that on destruction will call Update.
Callers that are fine with Update being called right away can skip
storing the object in a variable and thereby call Update immediately,
and callers that want to call Update later can keep the object around.
This new design reduces the risk that someone will forget calling
Update.
