[e2e] MySQL e2e test could pass even MySQL driver downloaded failure.

[wu-sheng]

We detected a high priority e2e test issue at #4335, the download link of MySQL driver is dead, but the e2e test could pass every time.

This is a high priority test issue, which makes reviewers can't use the test to verify the codes. @kezhenxu94 please take this as the 1st priority thing to fix.

[wu-sheng]

The download link will be fixed through #4335, but we need to invest why and fix it ASAP.

[dmsolr]

@kezhenxu94 , if you don't have time, I can submit a PR to pre-install the driver in e2e-container image.

[wu-sheng]

@dmsolr The download link has been fixed, the issue is why the test passed when the download fails

[dmsolr]

got it.

[kezhenxu94]

The e2e still passed because the failure (download) stops the replacement of application.yaml, and it falls back to H2 storage, this is fixed by SkyAPMTest/e2e-container@bf4cee3 and I just released e2e-container 1.5 https://hub.docker.com/r/skyapm/e2e-container/tags?page=1&ordering=last_updated since @dmsolr you're upgrading the container versions in your PR, please upgrade them to 1.5