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/android/util.go b/android/util.go
index 698a856..de4ca4d 100644
--- a/android/util.go
+++ b/android/util.go
@@ -302,6 +302,24 @@
 	return removed, result
 }
 
+// FirstUniqueFunc returns all unique elements of a slice, keeping the first copy of
+// each.  It does not modify the input slice. The eq function should return true
+// if two elements can be considered equal.
+func FirstUniqueFunc[SortableList ~[]Sortable, Sortable any](list SortableList, eq func(a, b Sortable) bool) SortableList {
+	k := 0
+outer:
+	for i := 0; i < len(list); i++ {
+		for j := 0; j < k; j++ {
+			if eq(list[i], list[j]) {
+				continue outer
+			}
+		}
+		list[k] = list[i]
+		k++
+	}
+	return list[:k]
+}
+
 // FirstUniqueStrings returns all unique elements of a slice of strings, keeping the first copy of
 // each.  It does not modify the input slice.
 func FirstUniqueStrings(list []string) []string {