Adding android typings for API levels from 17 to 27
BREAKING CHANGES:
There is no longer added `I` prefix in the names of the interfaces. For example `android.view.IMenuItem` is now `android.view.MenuItem`. This matches the original name of the interface in the android framework.
recycleNativeView filed now accepts: "always" | "never" | "auto". Always will recycle the nativeView no matter if its nativeView or android proprties are accessed. Never will disable recycling. Auto will recycle it only if nativeView and android properties are not accessed.
Call native setters once when a page is instantiated.
Fix background not being reset, Label's background is now set to background, not layer
Make the nativeView field instead of property for performance reasons
* fix padding on text-view & text-field
text-base is now snapshotable
view.android is now snapshotable
* createNativeView returns the nativeView for android
Fix image tests
Implement test for image loaded from res://
EffectivePaddings updated when nativeView have some from its native theme
* Remove Bindable.
Fix Observable & ObservableArray tests
Fix formattedString text
Change implementation of Span, FormattedString & TextBase
properties valueChange called before native setter
* revetred formattedString tests asserts - formattedText update text property again
properties - when getting value we now use always property name instead of key (using key could return undefined for property that is set to its default value)
updated fontSize & fontInternal properties on all controls
fix font properties so that fontInternal is reset if the new font is the same as Font.default
* fix tslint errors
moved some native setters from TabView to TabViewItem.
shorthand properties converters now accounts for unsetValue.
better formatting for test duration.
