Update Java-Client to 7.1.0

[mrk-han]

https://github.com/appium/java-client/releases/tag/v7.1.0

[BUG FIX] Platform Name enforced on driver creation is avoided now. appium/java-client#1164

[BUG FIX] Null pointer exceptions when calling getCapabilities is handled better. appium/java-client#1094

[BUG FIX] Error message on session creation is improved. appium/java-client#994