Some tests are limited to only Linux, when they should also pass for
Android.
Additionally, InputStream.swift.gyb was disabled for Android ARMv7, but
wasn't for Android AArch64, which allow me to find the error on it and
fix it on #24521.
Finally, StringLowercasedUppercased is interesting in Android because it
checks the used ICU is correct for performing the tasks that the stdlib
needs.