adjust exclusion file to disable WebRtcAecDumpBrowserTest.TwoCallsWithAecDump

on Dr.Memory bot

TBR=juberti@chromium.org
BUG=389132
NOTRY=true

Review URL: https://codereview.chromium.org/534603003

Cr-Commit-Position: refs/heads/master@{#292928}

tools/valgrind/gtest_exclude/content_browsertests.gtest-drmemory_win32.txt

 # crbug.com/389132
-WebRtcAecDumpBrowserTest.*CallWithAecDump*
+WebRtcAecDumpBrowserTest.*WithAecDump*
 
 # http://code.google.com/p/drmemory/issues/detail?id=1528
 # Un-analyzed test failures: