tools/android: Add support for creating Android virtual devices

Introduce ``tools/android/install_base.sh`` [1] script to install
Android command line tools including necessary platforms and
system-images for Linux and create Android Virtual Devices (AVD) for
Pixel 6 with Android v12 & v14 as well as an Android virtual *desktop*
device (v13) for ChromeOS tests.

[1] Forked from https://github.com/ARM-software/lisa/blob/main/install_base.sh

Signed-off-by: Metin Kaya <metin.kaya@arm.com>

doc/tools.rst

@@ -0,0 +1,43 @@
+Tools
+=====
+
+Android
+-------
+
+``tools/android/install_base.sh`` script installs Android command line tools
+for Linux and creates Android Virtual Devices (AVD).
+
+The script creates ``android-sdk-linux`` directory under ``tools/android`` and
+sets it as ``ANDROID_HOME`` directory (see
+https://developer.android.com/tools/variables).
+
+Your ``ANDROID_USER_HOME`` and ``ANDROID_EMULATOR_HOME`` environment variables
+point to ``tools/android/android-sdk-linux/.android``. Hence, removing
+``android-sdk-linux`` folder will clean all artefacts of ``install_base.sh``.
+
+It fetches Android command line tools, then installs Android SDK
+Platform-Tools, SDK Platform 31 (for Android 12) & 34 (for Android 14), and
+Google APIs for platforms 31 & 34 for the associated ABI type.
+
+Finally the script creates AVDs per Pixel 6 for Android 12 & 14.
+
+Shell commands below illustrate how to list available AVDs and run them via
+Android emulator:
+
+.. code:: shell
+
+   ANDROID_HOME="/devlib/tools/android/android-sdk-linux"
+   export ANDROID_HOME
+   EMULATOR="${ANDROID_HOME}/emulator/emulator"
+
+   export ANDROID_EMULATOR_HOME="${ANDROID_HOME}/.android"
+
+   # List available AVDs:
+   ${EMULATOR} -list-avds
+
+   # Run devlib-p6-14 AVD in emulator:
+   ${EMULATOR} -avd devlib-p6-14 -no-window -no-snapshot -memory 2048 &
+
+   # After ~30 seconds, the emulated device will be ready:
+   adb -s emulator-5554 shell "lsmod"
+