You can search for packages and package contents with apt-cache:
> apt-cache search opengels
mesa-utils-extra - Miscellaneous Mesa utilies (opengles, egl)
The output says that OpenGLES probably is in the package mesa-utils-extra. Mesa 3D has a project page for OpenGLES and writes there:
Mesa implements OpenGL ES 1.1 and OpenGL ES 2.0. More informations about OpenGL ES can be found at http://www.khronos.org/opengles/.
EGL is also built into Mesa:
> apt-cache search mesa | grep -i egl
mesa-utils-extra - Miscellaneous Mesa utilies (opengles, egl)
libegl1-mesa - free implementation of the EGL API -- runtime
libegl1-mesa-dbg - free implementation of the EGL API -- debugging symbols
libegl1-mesa-dev - free implementation of the EGL API -- development files
libegl1-mesa-drivers - free implementation of the EGL API -- hardware drivers
libegl1-mesa-drivers-dbg - free implementation of the EGL API -- driver debugging symbols
So you need to install mesa-utils-extra and probably also libegl1-mesa.