Fill out RemoteViews methods for editing LayoutParams.

* All these methods are still hidden
* Methods take either a dimen or a value with a TypedValue COMPLEX_UNIT (as used for TYPE_DIMENSION)
* Rather than having 8 margin methods, I chose to have only 2, and create an @IntDef MarginType
* Created a set of methods in TypedValue for creating typed value data equivalent to that of dimension resources.

Bug: 175345582
Test: atest TypedValueTest
Change-Id: I3a8a5a1511158a6dbf55d4f9931ba100a369cb35