Build notice files from license metadata.

Switch from generate-notice-files.py and mergenotice.py to htmlnotice.

Bug: 151177513
Bug: 213388645
Bug: 210912771

Test: m droid dist reportmissinglicenses
Change-Id: I6cac049d24f35ec358c6f341a04f4ba6161703bf
diff --git a/apex/apex.go b/apex/apex.go
index 6d8a67a..cb88f02 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -414,8 +414,8 @@
 	// Processed file_contexts files
 	fileContexts android.WritablePath
 
-	// Struct holding the merged notice file paths in different formats
-	mergedNotices android.NoticeOutputs
+	// Path to notice file in html.gz format.
+	htmlGzNotice android.WritablePath
 
 	// The built APEX file. This is the main product.
 	// Could be .apex or .capex
@@ -487,11 +487,10 @@
 // for each of the files in case when the APEX is flattened.
 type apexFile struct {
 	// buildFile is put in the installDir inside the APEX.
-	builtFile   android.Path
-	noticeFiles android.Paths
-	installDir  string
-	customStem  string
-	symlinks    []string // additional symlinks
+	builtFile  android.Path
+	installDir string
+	customStem string
+	symlinks   []string // additional symlinks
 
 	// Info for Android.mk Module name of `module` in AndroidMk. Note the generated AndroidMk
 	// module for apexFile is named something like <AndroidMk module name>.<apex name>[<apex
@@ -528,7 +527,6 @@
 		module:              module,
 	}
 	if module != nil {
-		ret.noticeFiles = module.NoticeFiles()
 		ret.moduleDir = ctx.OtherModuleDir(module)
 		ret.requiredModuleNames = module.RequiredModuleNames()
 		ret.targetRequiredModuleNames = module.TargetRequiredModuleNames()