Support Android 16Kb pages compilation

[ospfranco]

Hi! Starting soon Google play apps need to enable 16kb memory pages. This includes any internal libraries such as aws-lc-rs. I've modified the compilation process for my own binary but the generated .so files that aws-lc-rs needs are compiled externally via cmake. I don't know how to enable 16kb compilation there.

As pointers.

For the rust libraries I use the following option in the RUST_FLAGS:

-Clink-arg=-Wl,-zmax-page-size=16384

For pure C++ Android libs I use the following option when compiling via Gradle:

-DANDROID_SUPPORT_FLEXIBLE_PAGE_SIZES

It would be good if this would already be baked in the compilation process of aws-lc-rs and on the meantime a workaround we can apply to compile the internal libraries with the 16kb pages support.

Thanks a lot for open sourcing the package again!

Link to the Android docs.