Android: AVD launcher: Replace partition-size spin box with "Advanced Options..."

The AVD launch feature in Qt Creator has a "partition-size" spin box which allows to override the partition-size of an existing AVD per launch. The size is passed via argument when launching the emulator.

If the overridden value differs from the value in the AVD configuration (which is predominantly the case), this can cause the Emulator starting slowly with the message "Cold Boot: different AVD configuration". That is the case when launching the AVD by turns from Qt Creator and Android Studio.

So, let's remove that spin box, and give the user instead a full "Advances Options..." feature like the SDK manager already has: