## Meta -
OS:  OSX
Selenium Version:  3.5.2 (head of repo)
Browser:  iOS Safari
Browser Version:  iOS 10.3

## Expected Behavior - Using Selenium Grid the platformName would remain unchanged (keep behavior from 3.4)

## Actual Behavior - With Selenium Grid the platformName is overridden by platform in ImmutableCapabilities because iOS is not defined in Platform.java

## Steps to reproduce -
(already found a temporary fix with help from Simon and Jim)
Run an iOS test against SauceLabs with 3.4 and 3.5. As part of NewSessionPayload (in 3.5) when creating the capabilities iOS is an unrecognized platform so platformName (originally iOS) is set to platform (Mac), providing a bad set of capabilities for the test to actually run.
@Override
    public Platform family() {
      return LINUX;
    }
  },
  /**
   * Never returned, but can be used to request a browser running on any operating system.
   */
  ANY("") {
    @Override
    public boolean is(Platform compareWith) {
      return this == compareWith;
    }
  };
  private final String[] partOfOsName;
  private int minorVersion = 0;
  private int majorVersion = 0;
  private Platform(String... partOfOsName) {
    this.partOfOsName = partOfOsName;
  }
  public String[] getPartOfOsName() {
    return partOfOsName;
  }
  private static Platform current;
  /**
   * Get current platform (not necessarily the same as operating system).
   *
   * @return current platform
   */
  public static Platform getCurrent() {