[CI] Install protoc before calling yarn

Summary:
'yarn cleaninstall' now requires protoc to be available for the
rust-node-addon package to successfully build.

Move install_protobuf.sh to a shared location as non-android workflows may
need to use the script

Test Plan: https://buildkite.com/comm/android-build/builds/9597#0185a732-17b0-4b0f-aad2-40d30bba8c06 passes

Reviewers: atul, varun, ashoat

Reviewed By: atul, varun

Subscribers: tomek

Differential Revision: https://phab.comm.dev/D6255