Improve Android cross-compile scenario by covering extra cases

[uilianries]

Greetings, this issue is a follow-up over #3351 and conan-io/conan-center-index#24915

The current documentation https://docs.conan.io/2/examples/cross_build/android/ndk.html#examples-cross-build-android-ndk shows how to cross-compile to Android by using a NDK installed in the system in a very regular case using CMake. It works for the example, but when exploring other cases, like trying to build using autotools or not well prepared project, it may fail.

It would be nice updating the documentation by adding some hints, as cross-building is always a harder scenario and not always work at first try, being frustrating for users.

• Add android-ndk/r25c as tool-requirement, as alternative. That CCI package configures everything already, including ndk-path.
• Complement the configuration with compiler path (tools.build:compiler_executables) to cover other scenarios when ndk path is not enough (e.g. Boost recipe using B2)

/cc @cjserio @neobrain

[neobrain]

Might be helpful to collect more packages here that don't compile with the recipe from the documentation:

• freetype/2.13.2 (as mentioned in [package] Boost/1.85.0: Cannot compile for Android conan-center-index#24915 (comment))
• will add more if I find any :)