Move result.h from init to libbase

The Result, Error, ErrnoError are quite generic. Moving them from init
to libbase so that they can be used from other places.

Bug: 132145659
Test: libbase_test
Change-Id: Id774a587f74380fadd7a0fc88c0aa892c3d9a489
diff --git a/base/Android.bp b/base/Android.bp
index 58d3a50..25a9f68 100644
--- a/base/Android.bp
+++ b/base/Android.bp
@@ -141,6 +141,7 @@
         "parsenetaddress_test.cpp",
         "properties_test.cpp",
         "quick_exit_test.cpp",
+        "result_test.cpp",
         "scopeguard_test.cpp",
         "stringprintf_test.cpp",
         "strings_test.cpp",