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Summary:Add slashes for escape characters in shell script which query elements
Closes https://github.com/facebook/WebDriverAgent/pull/136

Differential Revision: D3195981

Pulled By: marekcirkos

fb-gh-sync-id: f0f1739e59008579cf9ab4276dbe780be3950847
fbshipit-source-id: f0f1739e59008579cf9ab4276dbe780be3950847

ymin/WebDriverAgent,drptbl/WebDriverAgent,zenzhu/WebDriverAgent,qa-dev/WebDriverAgent,qa-dev/WebDriverAgent,Gogle/WebDriverAgent,calabash/WebDriverAgent,calabash/WebDriverAgent,riccoyu/WebDriverAgent,qa-dev/WebDriverAgent,rafael-chavez/WebDriverAgent,PiranhaTeam/WebDriverAgent,PiranhaTeam/WebDriverAgent,rafael-chavez/WebDriverAgent,zenzhu/WebDriverAgent,b1ueshad0w/WebDriverAgent,zenzhu/WebDriverAgent,drptbl/WebDriverAgent,Gogle/WebDriverAgent,b1ueshad0w/WebDriverAgent,ymin/WebDriverAgent,calabash/WebDriverAgent,riccoyu/WebDriverAgent,drptbl/WebDriverAgent,ymin/WebDriverAgent,b1ueshad0w/WebDriverAgent,riccoyu/WebDriverAgent,qa-dev/WebDriverAgent,b1ueshad0w/WebDriverAgent,PiranhaTeam/WebDriverAgent,rafael-chavez/WebDriverAgent,PiranhaTeam/WebDriverAgent,PiranhaTeam/WebDriverAgent,Gogle/WebDriverAgent,Gogle/WebDriverAgent,ymin/WebDriverAgent,riccoyu/WebDriverAgent