Log CallStats for more api calls

+ CALL_TYPE_SET_SCHEMA
+ CALL_TYPE_GET_DOCUMENTS
+ CALL_TYPE_REMOVE_DOCUMENTS
+ CALL_TYPE_FLUSH

Bug: b/173532925
Test: ./gradlew  -Pandroidx.allWarningsAsErrors
appsearch: appsearch:build appsearch:appsearch-compiler:build
appsearch: appsearch-local-storage:build  icing:build
icing: nativeLib:build appsearch:appsearch:connectedCheck
appsearch: appsearch-local-storage:connectedCheck
appsearch: appsearch:lintDebug
appsearch: appsearch-local-storage:lintDebug
Change-Id: Ib1521b0920d40828f30a7ee00e6996ab032c9ef6