Fix typos on descriptions for telemetry dashboards

There are could of typos/recommendations requested in the following document:

https://docs.google.com/spreadsheets/d/1t28dcgO9uXfXXCUpX0Qb5s7-TwnQH14Ytd04FcSMLNE/edit#gid=0

Some of them are simple typos/naming improvements that would be nice to add:

• The dashboards have duplicate titles (e.g. MySQL version, PostrgeSQL version and MongoDB version is listed twice). Can we change the titles so the they describe their distinctions?

• The dashboard in the middle row (MySQL/PostgreSQL/MongoDB Version) has a column called 'event_time'. What does that mean and can we change to an intuitive to understand title?

• The OS is displayed as a number. What is this referring to? What OS is it?

• Feature usage: There are two rows with the same information (row 2 and 3). Why?

• Alerting: Could we remove the pie charts? I don't think they offer extra insight

• Alerting: Currently Found Problems: Yestarday typo

• What does 'generated per execution mean? Can we replace it with an intuitive to understand title please?