[APM] Breakdown charts doesn't show any data for small time ranges

[sorenlouv]

When the chart is zoomed in far enough that we cannot show any data (<30s) because our collection interval is larger, we don't show anything which is not helpful to the user either.

Possible suggestions:

• show a textual hint to the user as to why we can't show any data.
• Make metric sets interval size configurable via kibana.yml

[elasticmachine]

Pinging @elastic/apm-ui