fix: allow users to specify --device without value

[szymonrybczak]

Summary:

Fixes #2262.

In #2078 --device was accidentally removed, and in #2086 the flag was restored, but with a small change where now --device flag accept value wrapped <> instead of []:

• Current implementation:
  

  cli/packages/cli-platform-apple/src/commands/runCommand/runOptions.ts

  Line 46 in f50cc16

  name: '--device <string>',

• Old one:
  

  cli/packages/cli-platform-ios/src/commands/buildIOS/index.ts

  Line 227 in a2eb8c0

  name: '--device [string]',

that caused a regression, because with <> value is required, but with [] is optional.

Test Plan:

1. Clone the repository and do all the required steps from the Contributing guide
2. Plug physical device to computer
3. Run this command:

node /path/to/react-native-cli/packages/cli/build/bin.js run-ios --device

4. First physical device should be picked:

❯ yarn ios --device
yarn run v1.22.19
$ react-native run-ios --device
info Found Xcode workspace "RN0732.xcworkspace"
info Using first available device named "iPhone Szymon" due to lack of name supplied.

Checklist

• Documentation is up to date to reflect these changes.
• Follows commit message convention described in CONTRIBUTING.md