Building subset "Libs" does not work when cross compiling with the Android NDK

[CircuitRCAY]

Description

Cross-compiling with the Android NDK is in "bits and pieces", and the build-android-rootfs.sh script in eng/common/cross is not exactly up to date, instead having to use a different set of subsets.

Build Steps

./eng/common/cross/build-android-rootfs.sh arm64 # on the root directory
ROOTFS_DIR=$(realpath ~/runtime/.tools/android-rootfs/android-ndk-r21/sysroot) ./build.sh --cross --arch arm64 --subset Libs

Expected Behaviour

• Compiles successfully without any issues or missing libraries.

Observed Behaviour

• Fails and errors on missing libSystem.IO.Ports.so library.

Configuration

• .NET Version: N/A
• OS: Linux innovare 5.8.7-arch1-1 #1 SMP PREEMPT Sat, 05 Sep 2020 12:31:32 +0000 x86_64 GNU/Linux
• Architecture:
  • Host: x86_64
  • Guest: arm64

Regression?

N/A

Other information

Log of the build: https://haste.soulja-boy-told.me/udacegifim.txt
Related issues: These commands were partially modified from #33237.

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