Push back the expiry of two ChromiumAndroidLinker histograms.

These are still useful metrics to record for Android startup-time
performance analysis.

Bug: 975734
Change-Id: I8f8c7e8f40d891dbd289b55dd346b01020ca6278
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1682877
Reviewed-by: Jesse Doherty <jwd@chromium.org>
Commit-Queue: Robert Sesek <rsesek@chromium.org>
Cr-Commit-Position: refs/heads/master@{#674187}
1 file changed