Fix import in MetricExporter to fix build.

[bogdandrutu]

No description provided.

[codecov-io]

Codecov Report

❗ No coverage uploaded for pull request base (master@047d43e). Click here to learn what that means.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master     #851   +/-   ##
=========================================
  Coverage          ?   79.14%           
  Complexity        ?      792           
=========================================
  Files             ?      106           
  Lines             ?     2862           
  Branches          ?      269           
=========================================
  Hits              ?     2265           
  Misses            ?      495           
  Partials          ?      102

Impacted Files	Coverage Δ	Complexity Δ
...entelemetry/sdk/metrics/export/MetricExporter.java	0% <ø> (ø)	0 <0> (?)

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[jkwatson]

beat me to it again! I just ran into this myself.