Add API's for normalizing MIME's and URI's.

Helps developers create well-behaved intents:
- lower case MIME data type
- strip parameters from MIME content types
- lowercase URI scheme

The new API's are
normalizeAndSetType()
normalizeAndSetData()
normalizeAndSetDataAndType()
Uri.normalize()
normalizeMimeType()

Change-Id: Ib5c907897f39b1f705bcc4c9103ba1e6f316380b