Include stubs type in metalava.rsp filename

Currently, metalava.rsp filepath for both the everything and the
exportable stubs type are identical, which may lead to incremental build
issues. This change resolves such issue by including the stubs type in
the metalava.rsp filename.

These files cannot be modified as ".../everything/metalava.rsp" and
".../exportable/metalava.rsp" as `FlagWithRspFileInputList(...)`
enforces the rsp filepath to be outside of the outdir, which is
".../everything/" and ".../exportable/", respectively. Thus, this change
continues to generate the rsp file to be generated in the module outdir,
but modifies the name of the rsp files as "everything.metalava.rsp" and
"exportable.metalava.rsp".

This change also simplifies the parameters in metalavaCmd(...) for the
simplicity of the method parameters.

Test: m nothing and inspect output for the everything and the exportable stubs
Bug: 336360490
Change-Id: Ifd4e89ef69808e79ea720199677585f0217f7c1c