Revert "Expose 'release' build mode in build.sh"
Revert "Expose 'release' build mode in build.sh"

This reverts commit dde25f57b2437957e6c1daa4f4cab22d58fc7d9c.

realm/realm-core,realm/realm-core,realm/realm-core,realm/realm-core,realm/realm-core,realm/realm-core,realm/realm-core