shell_tools: Fix pipe symbol formatting in README.md
shell_tools: Fix pipe symbol formatting in README.md

Change-Id: Ida2dde1a571046e6f8b9fffc295bd4f12aa6dc4d
Signed-off-by: Adrian DC <01fb3892f39957945220431e7409156544d2f041@gmail.com>

AdrianDC/android_development_shell_tools,AdrianDC/android_development_shell_tools