RFR: 8253232: G1Analytics::compute_pause_time_ratios() uses wrong pause times in calculation

[Ivan Walulya]

Changed to consider only gc pause times within the long time interval.
Testing: Tier 1

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Commit messages:
 - 8253232: G1Analytics::compute_pause_time_ratios() uses wrong pause times

Changes: https://git.openjdk.java.net/jdk/pull/210/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=210&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8253232
  Stats: 2 lines in 1 file changed: 1 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/210.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/210/head:pull/210

PR: https://git.openjdk.java.net/jdk/pull/210