This CL mainly changes:
a) moving the interface in struct provider_vtab to std::function;
b) code cleanup, such as moving the declaration closer to the uses,
using explicit type conversion.
Test: recovery_component_test
Test: minadbd_test
Test: Sideload a package on marlin.
Change-Id: Id0e3c70f1ada54a4cd985b54c84438c23ed4687e
Distinguish our "services.cpp" more clearly from the regular adbd
"services.cpp", and remove a few useless includes of "sysdeps.h".
Change-Id: Ided4945a3ac5916133322ca7e95fa51add9abaa4
