build: fix android build, fix symbol redefinition
build: fix android build, fix symbol redefinition

linux-core defines uv_get_free_memory() and uv_get_total_memory() so
don't include sysinfo-memory.c too. The cmake and autotools builds
don't do so either.

PR-URL: https://github.com/libuv/libuv/pull/2542
Reviewed-By: Colin Ihrig <838f779c91673db29b8572ea3f54d191d3878ae2@gmail.com>
Reviewed-By: Saúl Ibarra Corretgé <8a7991f6950ea189abf159d6ec98d2fcc13dc5f6@gmail.com>

unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso