Set previous_api correctly for java_sdk_library

Metalava used this attribute to potentially re-write some nullness
annotations from @Nullable to @RecentlyNonNull, and not doing so can
cause problems when compiling kotlin.

Bug: 176092452
Test: m art.module.public.api.stubs && \
      rm -rf /tmp/lib && \
      unzip -qd /tmp/lib art.module.public.api.stubs.jar && \
      javap -v /tmp/lib/java/util/concurrent/ConcurrentHashMap.class | \
      grep Recently
Change-Id: I9012798f27e39d9a53dbcf0976548f6cec2d3150

java/droiddoc.go

@@ -1082,6 +1082,10 @@ func (d *Droidstubs) DepsMutator(ctx android.BottomUpMutatorContext) {
 	// If requested clear any properties that provide information about the latest version
 	// of an API and which reference non-existent modules.
 	if Bool(d.properties.Check_api.Ignore_missing_latest_api) {
+		previousApi := android.SrcIsModule(String(d.properties.Previous_api))
+		if previousApi != "" && !ctx.OtherModuleExists(previousApi) {
+			d.properties.Previous_api = nil
+		}
 		ignoreMissingModules(ctx, &d.properties.Check_api.Last_released)
 
 		// If the new_since references a module, e.g. :module-latest-api and the module

java/sdk_library.go

@@ -1271,6 +1271,7 @@ func (module *SdkLibrary) createStubsSourcesAndApi(mctx android.DefaultableHookC
 		Merge_annotations_dirs           []string
 		Merge_inclusion_annotations_dirs []string
 		Generate_stubs                   *bool
+		Previous_api                     *string
 		Check_api                        struct {
 			Current                   ApiToCheck
 			Last_released             ApiToCheck
@@ -1363,6 +1364,7 @@ func (module *SdkLibrary) createStubsSourcesAndApi(mctx android.DefaultableHookC
 	if !apiScope.unstable {
 		// check against the latest released API
 		latestApiFilegroupName := proptools.StringPtr(module.latestApiFilegroupName(apiScope))
+		props.Previous_api = latestApiFilegroupName
 		props.Check_api.Last_released.Api_file = latestApiFilegroupName
 		props.Check_api.Last_released.Removed_api_file = proptools.StringPtr(
 			module.latestRemovedApiFilegroupName(apiScope))