The server is currently a JAR, but it may ba an APK or a DEX, so the
variable name should not contain the type.
Rename the environment variable, the Meson options and the C
definitions.
Add a script to simplify the execution of scrcpy generated in a specific
build directory.
To run scrcpy generated in builddir, with a video size of 1024:
./run builddir -m 1024