Previously, when an input device was connected or disconnected, we would
recreate all devices. This commit makes it so we only touch the relevant
device instead. This matters because recreating a device causes us to
drop all held buttons for that device. Due to Android only delivering
inputs as events, we're unable to poll for currently held buttons when
recreating a device.

This recently became a problem for users of Ayn devices due to a
firmware update. Every now and then, something about the display
viewports changes, triggering an update to an input device that I assume
is a touch input device. This input device isn't something users
normally map in Dolphin's controller settings, but it changing was
causing Dolphin to drop all held buttons for the device's built-in
gamepad as well as any other connected gamepads.

Without this, there was a bug where if you turned the device's screen
off and on again while in the advanced mapping dialog, the input
indicators would stop updating. This is because turning the screen on
again causes devices to refresh, which causes all devices to be
recreated, leaving the AdvancedMappingControlViewHolders stuck
referencing controls belonging to devices that are no longer being
updated.

In NandPaths.cpp, the `std::initializer_list<char>` of illegal characters has been turned into a `char[]` (similar to the one in GameList.cpp).

The reverse iteration in ResourcePack.cpp seemed to provide no benefits, and doing without it it seemed to have no ill effects.

This was broken by a9a9fdd9e9. Because Init didn't run, the Android
input backend would crash whenever it tried to call into JVM code.