`./wpt install-android-emulator` (without `--debug`) drops the user into a pdb prompt when a JRE isn't installed

[gsnedders]

% ./wpt install-android-emulator
...
INFO:root:Installing Android packages platform-tools build-tools;37.0.0 platforms;android-37.1 emulator
The operation couldn’t be completed. Unable to locate a Java Runtime.
Please visit http://www.java.com for information on installing Java.

Traceback (most recent call last):
  File "/Volumes/gsnedders/projects/Safari/Safari-WebDriver-Actions/wpt/tools/wpt/android.py", line 313, in run_install
    install(logger, **kwargs)
  File "/Volumes/gsnedders/projects/Safari/Safari-WebDriver-Actions/wpt/tools/wpt/android.py", line 264, in install
    install_android_packages(logger, paths, packages, prompt=prompt)
  File "/Volumes/gsnedders/projects/Safari/Safari-WebDriver-Actions/wpt/tools/wpt/android.py", line 185, in install_android_packages
    subprocess.run(cmd, check=True, input=input_data)
  File "/AppleInternal/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/subprocess.py", line 528, in run
    raise CalledProcessError(retcode, process.args,
subprocess.CalledProcessError: Command '['/Volumes/gsnedders/projects/Safari/Safari-WebDriver-Actions/wpt/_venv3/android/android-sdk-darwin/cmdline-tools/12.0/bin/sdkmanager', 'platform-tools', 'build-tools;37.0.0', 'platforms;android-37.1', 'emulator']' returned non-zero exit status 1.
> /AppleInternal/Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/subprocess.py(528)run()
-> raise CalledProcessError(retcode, process.args,
(Pdb) 

--debug is meant to have this behaviour, but without it we shouldn't do this.

[jgraham]

#61714