Generate info about the selected app variant in platform builds

This is a followup to aosp/2999198 and adds information about apps.

Each app will have an entry in this file with the following properties
- Name, mandatory
- Is_prebuilt, mandatory
- Prebuilt_info_file_path, optional

Implementation details
- Move prebuiltInfoProvider out of build/soong/apex to
  build/soong/android. This allows build/soong/java to use it.
- Introduce a new `prebuilt_info` prop to `android_app_set` and
  `android_app_import`
- All app module types will set a prebuiltInfoProvider in
  GenerateAndroidBuildActions, including the source app module types

Test: m nothing --no-skip-soong-tests
Test: m out/soong/prebuilt_info.json
Test: ls -l out/soong/prebuilt_info.json --human-readable
-rw------- 1 spandandas primarygroup 317K Mar 11 23:46 out/soong/prebuilt_info.json

Test: #modified trunk_staging.locally to select prebuilts of some
mainline apps. Spot-checked that `is_prebuilt` and
`prebuilt_info_file_path` get populated appropriately

Bug: 327480225
Change-Id: I5078e0ec26c9568194550909962b90111a5223f7

apex/apex.go

@@ -2428,29 +2428,14 @@ func (a *apexBundle) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 	a.providePrebuiltInfo(ctx)
 }
 
-var prebuiltInfoProvider = blueprint.NewProvider[prebuiltInfo]()
-
-// contents of prebuilt_info.json
-type prebuiltInfo struct {
-	// Name of the apex, without the prebuilt_ prefix
-	Name string
-
-	Is_prebuilt bool
-
-	// This is relative to root of the workspace.
-	// In case of mainline modules, this file contains the build_id that was used
-	// to generate the mainline module prebuilt.
-	Prebuilt_info_file_path string `json:",omitempty"`
-}
-
 // Set prebuiltInfoProvider. This will be used by `apex_prebuiltinfo_singleton` to print out a metadata file
 // with information about whether source or prebuilt of an apex was used during the build.
 func (a *apexBundle) providePrebuiltInfo(ctx android.ModuleContext) {
-	info := prebuiltInfo{
+	info := android.PrebuiltInfo{
 		Name:        a.Name(),
 		Is_prebuilt: false,
 	}
-	android.SetProvider(ctx, prebuiltInfoProvider, info)
+	android.SetProvider(ctx, android.PrebuiltInfoProvider, info)
 }
 
 // Set a provider containing information about the jars and .prof provided by the apex

apex/apex_singleton.go

@@ -149,10 +149,10 @@ type apexPrebuiltInfo struct {
 }
 
 func (a *apexPrebuiltInfo) GenerateBuildActions(ctx android.SingletonContext) {
-	prebuiltInfos := []prebuiltInfo{}
+	prebuiltInfos := []android.PrebuiltInfo{}
 
 	ctx.VisitAllModules(func(m android.Module) {
-		prebuiltInfo, exists := android.SingletonModuleProvider(ctx, m, prebuiltInfoProvider)
+		prebuiltInfo, exists := android.SingletonModuleProvider(ctx, m, android.PrebuiltInfoProvider)
 		// Use prebuiltInfoProvider to filter out non apex soong modules.
 		// Use HideFromMake to filter out the unselected variants of a specific apex.
 		if exists && !m.IsHideFromMake() {

apex/prebuilt.go

@@ -827,15 +827,15 @@ func (p *prebuiltCommon) provideApexExportsInfo(ctx android.ModuleContext) {
 // Set prebuiltInfoProvider. This will be used by `apex_prebuiltinfo_singleton` to print out a metadata file
 // with information about whether source or prebuilt of an apex was used during the build.
 func (p *prebuiltCommon) providePrebuiltInfo(ctx android.ModuleContext) {
-	info := prebuiltInfo{
-		Name:        p.BaseModuleName(), // BaseModuleName ensures that this will not contain the prebuilt_ prefix.
+	info := android.PrebuiltInfo{
+		Name:        p.BaseModuleName(),
 		Is_prebuilt: true,
 	}
 	// If Prebuilt_info information is available in the soong module definition, add it to prebuilt_info.json.
 	if p.prebuiltCommonProperties.Prebuilt_info != nil {
 		info.Prebuilt_info_file_path = android.PathForModuleSrc(ctx, *p.prebuiltCommonProperties.Prebuilt_info).String()
 	}
-	android.SetProvider(ctx, prebuiltInfoProvider, info)
+	android.SetProvider(ctx, android.PrebuiltInfoProvider, info)
 }
 
 func (p *Prebuilt) GenerateAndroidBuildActions(ctx android.ModuleContext) {