Re-enable minidump tests on Betty

Re-enables the Telemetry minidump symbolization tests on CrOS Betty
devices, as the failures that caused them to be disabled appear to no
longer be an issue.

Bug: 1038043

Change-Id: Ibe335c60cb85ed29bd478dbfe6369d7e40d5c4e0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2321402Reviewed-by: John Chen <johnchen@chromium.org>
Commit-Queue: Brian Sheedy <bsheedy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#792145}

tools/perf/core/minidump_unittest.py

@@ -33,11 +33,8 @@ class BrowserMinidumpTest(tab_test_case.TabTestCase):
   @decorators.Isolated
   # Minidump symbolization doesn't work in ChromeOS local mode if the rootfs is
   # still read-only, so skip the test in that case.
-  # TODO(crbug.com/1038043): Test is failing on chromeos-betty-chrome.
   @decorators.Disabled(
       'chromeos-local',
-      'chromeos-board-betty',
-      'chromeos-board-betty-pi-arc',
       'win'  # https://crbug.com/1084931
   )
   def testSymbolizeMinidump(self):
@@ -81,11 +78,8 @@ class BrowserMinidumpTest(tab_test_case.TabTestCase):
   @decorators.Isolated
   # Minidump symbolization doesn't work in ChromeOS local mode if the rootfs is
   # still read-only, so skip the test in that case.
-  # TODO(crbug.com/1038043): Test is failing on chromeos-betty-chrome.
   @decorators.Disabled(
       'chromeos-local',
-      'chromeos-board-betty',
-      'chromeos-board-betty-pi-arc',
       'win'  # https://crbug.com/1084931
   )
   def testMultipleCrashMinidumps(self):