Merge changes from topic "reland-hack-rv64-libc++" into main

* changes:
  Revert "Revert "Set VIC as minimum SDK version for riscv64""
  Revert "Revert "Use prebuilt NDK libc++ for rv64.""

cc/api_level.go

@@ -31,7 +31,11 @@ func MinApiForArch(ctx android.EarlyModuleContext,
 	case android.Arm64, android.X86_64:
 		return android.FirstLp64Version
 	case android.Riscv64:
-		return android.FutureApiLevel
+		apiLevel, err := android.ApiLevelFromUser(ctx, "VanillaIceCream")
+		if err != nil {
+			panic(err)
+		}
+		return apiLevel
 	default:
 		panic(fmt.Errorf("Unknown arch %q", arch))
 	}

cc/stl.go

@@ -80,8 +80,7 @@ func (stl *stl) begin(ctx BaseModuleContext) {
 			return ""
 		}
 		s = deduplicateStlInput(s)
-		archHasNDKStl := ctx.Arch().ArchType != android.Riscv64
-		if ctx.useSdk() && ctx.Device() && archHasNDKStl {
+		if ctx.useSdk() && ctx.Device() {
 			switch s {
 			case "", "system":
 				return "ndk_system"