def installed_packages(device_serial)
      packages = run_adb_command("adb -s #{device_serial} shell pm list packages",
                                 print_all: true,
                                 print_command: true)
      packages.split("\n").map { |package| package.gsub("package:", "") }
    end
def installed_packages(device_serial)
      packages = run_adb_command("adb -s #{device_serial} shell pm list packages",
                                 print_all: true,
                                 print_command: true)
      packages.split("\n").map { |package| package.gsub("package:", "") }
    end
Return an array of packages that are installed on the device