doc: README: update android build instructions
doc: README: update android build instructions

Remove references to the old Android "SDK Tools". Those obsolete tools
are still shipped in the Android Studio package. They are also replaced
by the newer "commandline-tools" package, distributed separately.

Those "SDK Tools" were the last parts needing the old Java 8.0 Runtime
Environment.

See: https://developer.android.com/studio/releases/sdk-tools

Signed-off-by: Julien Olivain <e017b3aecfdd2dc1bdcf241eeb088a15ff1e3ada@free.fr>

jolivain/glslsandbox-player,jolivain/glslsandbox-player,jolivain/glslsandbox-player,jolivain/glslsandbox-player