Ensure RBE_CXX_POOL and RBE_JAVA_POOL variables work as expected

These environment variables are not being passed onto compile actions created from makefiles. This change makes sure that these env variables are passed along so that we are able to update the C++ / Javac pool being used

Test: Ran a build with RBE_CXX_POOL=cpp_next to test the next pool
Bug: b/199774309
Change-Id: Icd47d3647b962a6c3ac712369466d5502b817fd7