Auto merge of #23324 - marcinwiacek:ubuntu1904, r=jdm

Changes for Ubuntu/Ubuntu 19.04 in bootstrap.py

Update handling Ubuntu distributions:

1. script correctly returns error when some version is/was not supported (checked with Ubuntu 19.04)
2. for Ubuntu 19.04 Disco Dingo there are correct packages installed

Note: this is my commit to this project, please forgive any mistakes.

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