Add Gflags for fusion strategy and make it local to executor (#73668)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/73668
Test Plan: Imported from OSS
Reviewed By: dagitses
Differential Revision: D34598128
Pulled By: eellison
fbshipit-source-id: a67a258d5dde8ad81bf19151bcf7a4da1321a2c0
(cherry picked from commit 578d3150f1557c4df91d35ad464896610bf8c23b)
