Add mailto contact scheme support to MAP Client.

Bug: 266796373
Bug: 271386921
Tag: #feature
Test: atest MapClientStateMachineTest
(cherry picked from https://android-review.googlesource.com/q/commit:2a013965f80af744cebc33b90de17343ef231d7c)
Merged-In: I7f2a3637b773c4e25d2f4033a82bc70724b70104
Change-Id: I7f2a3637b773c4e25d2f4033a82bc70724b70104
Bug: 263323082