Extend FluentWait, so one can set custom polling strategy

[mykola-mokhnach]

Change list

Created extended FluentWait class with possibility to allow custom polling strategy. This might be quite useful while working with mobile interfaces where the initial transition animation creates main delay before an element appears on the screen. Having custom polling strategy set allows one to increase this initial polling delay, so the interface has enough time to finish the transition faster without being unnecessarily interrupted by Appium agent calls.

Types of changes

What types of changes are you proposing/introducing to Java client?
Put an x in the boxes that apply

• No changes in production code.
• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Details

I don't really like the implementation myself, since it is necessary to access private fields of the parent class via reflection API. Please let me know if you have better ideas on how to implement it.