If not argument is given, the app just sits and wait
for stdin input, this can be confusing for the user.
Add logic to display menu if no argument is given.
Test: metrics_dump
display menu
Test: metrics_dump [bugreport from sabrina-q.gz]
display mediadrm and widevine metrics
Test: metrics_dump --mediadrm [adb shell dumpsys media.metrics output]
display mediadrm metrics
Test: metrics_dump --widevine [adb shell dumpsys media.metrics output]
display widevine metrics
Test: metrics_dump [bugreport from sabrina-q.gz] --widevine
display menu because the order is app_name, options, input file
Bug: 180983850
Change-Id: I9b35f782d8f59663661148d3950f89e4724b6bce
Merged-In: I9b35f782d8f59663661148d3950f89e4724b6bce
0ac0ee50eb