Fix missing NOTICE targets for static libs that aren't available to
platform.

The NOTICE file generation depends on the NOTICE targets for all static
library dependencies. If such a dependency didn't have
//apex_available:platform it didn't get any AndroidMk entry and hence
no NOTICE target via soong_cc_prebuilt.mk. If it was then depended upon
by a binary or library that is accessible to platform, the NOTICE
dependency failed.

Normally such a dependency is invalid, but there are corner cases where
binaries go neither into platform nor any APEX module, and they can
legitimately have such dependencies (cf. b/152241137).

With this CL requests to skip installation of such a static libraries
are ignored so that they get AndroidMk entries, which will always have
LOCAL_UNINSTALLABLE_MODULE set.

Test: "m simpleperf_ndk" with https://r.android.com/1273016, which
  removes //apex_available:platform from libs that simpleperf_ndk
  depends on statically.
Bug: 152241137
Bug: 149217815
Change-Id: If36e85dd16ade56d4ec1d6744811df5a15b6242c
Merged-In: If36e85dd16ade56d4ec1d6744811df5a15b6242c
diff --git a/cc/library.go b/cc/library.go
index c7488ee..34b27a4 100644
--- a/cc/library.go
+++ b/cc/library.go
@@ -1303,6 +1303,18 @@
 	return android.CheckAvailableForApex(what, list)
 }
 
+func (library *libraryDecorator) skipInstall(mod *Module) {
+	if library.static() && library.buildStatic() && !library.buildStubs() {
+		// If we're asked to skip installation of a static library (in particular
+		// when it's not //apex_available:platform) we still want an AndroidMk entry
+		// for it to ensure we get the relevant NOTICE file targets (cf.
+		// notice_files.mk) that other libraries might depend on. AndroidMkEntries
+		// always sets LOCAL_UNINSTALLABLE_MODULE for these entries.
+		return
+	}
+	mod.ModuleBase.SkipInstall()
+}
+
 var versioningMacroNamesListKey = android.NewOnceKey("versioningMacroNamesList")
 
 func versioningMacroNamesList(config android.Config) *map[string]string {