Revert "Temporarily disable gmail deploy 180826.15"

This reverts commit e7ef7b80eb7147d66ecfdb34a04797aa3e471013.

Reason for revert: the problematic CL is reverted (go/r8g/37700)

Bug: 131370264
Change-Id: Ifcfd96ae0be3c44af434dddaaf9b3ae92c5fa6ae
diff --git a/tools/run_on_app.py b/tools/run_on_app.py
index d68ade3..a480214 100755
--- a/tools/run_on_app.py
+++ b/tools/run_on_app.py
@@ -141,7 +141,6 @@
 DISABLED_PERMUTATIONS = [
   # (app, version, type), e.g., ('gmail', '180826.15', 'deploy'),
   ('youtube', '13.37', 'deploy'), # b/120977564
-  ('gmail', '180826.15', 'deploy'), # b/131370264
 ]
 
 def get_permutations():