fix: Use lower case for Windows platform key in ElementMap

[valfirst]

Change list

Fixes #965
Fixes #774
Fixes #1247

Types of changes

What types of changes are you proposing/introducing to Java client?

• 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)

[mykola-mokhnach]

This should make no difference for Appium, since the comparison is anyway case-insensitive.

[valfirst]

@mykola-mokhnach I believe the problem comes from these lines where the keys to find are converted to lower case:

java-client/src/main/java/io/appium/java_client/internal/ElementMap.java

Lines 80 to 83 in 0be00cd

	ElementMap element = Optional.ofNullable(mobileElementMap.get(
	String.valueOf(platform).toLowerCase().trim()))
	.orElseGet(() -> mobileElementMap
	.get(String.valueOf(automation).toLowerCase().trim()));