rust: made-to-order rust staticlibs

Whenever any two Rust static libraries are included
as static libraries anywhere in a CC dependency tree, we sometimes
get duplicate symbol errors. To avoid this, we no longer
directly link multiple rust static libs to CC modules.

Instead, we build rust_ffi_rlib modules and produce the actual
static library that gets linked against the CC module based on
that CC module's full list of Rust rlib dependencies.

This introduces a new static_rlibs property for cc modules to
define the rust_ffi_rlib dependencies, which are then used to
generate the module above.

This CL is intended to deprecate rust_ffi_static. It leaves
rust_ffi_static and rust_ffi static variants in place until
the remaining rust_ffi_static declarations and uses can be
removed. In the meantime, rust_ffi_static produces
rust_ffi_rlib variants as well to make the transition easier.

Bug: 254469782
Test: m # with no changes
Test: m libapexsupport # with static_rlibs
Test: m libunwindstack # with static_rlibs
Test: m netsimd # with static_rlibs, no duplicate symbols
Test: m blueprint_tests # New Soong tests

Change-Id: I47e27ac967ef0cad46d398ebf59d8275929ae28a
diff --git a/apex/apex.go b/apex/apex.go
index ef57d7e..0fc5a5e 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -702,7 +702,12 @@
 func addDependenciesForNativeModules(ctx android.BottomUpMutatorContext, nativeModules ApexNativeDependencies, target android.Target, imageVariation string) {
 	binVariations := target.Variations()
 	libVariations := append(target.Variations(), blueprint.Variation{Mutator: "link", Variation: "shared"})
-	rustLibVariations := append(target.Variations(), blueprint.Variation{Mutator: "rust_libraries", Variation: "dylib"})
+	rustLibVariations := append(
+		target.Variations(), []blueprint.Variation{
+			{Mutator: "rust_libraries", Variation: "dylib"},
+			{Mutator: "link", Variation: ""},
+		}...,
+	)
 
 	// Append "image" variation
 	binVariations = append(binVariations, blueprint.Variation{Mutator: "image", Variation: imageVariation})