Use Metalava to get SDK metadata for devtools

Metalava, not Doclava, should be used to extract the metadata used in
devtools. The files created then need to be copied into the SDK.

Bug: 142480924
Test: m sdk
Change-Id: I7eb15341fde9520d51a696a6416a63e6c19c71f9
Merged-In: I7eb15341fde9520d51a696a6416a63e6c19c71f9
2 files changed