Clean up rust tests.

The list of required deps for testing is a lot shorter as we no longer
include as many prebuilt libraries and our list of stdlibs is much
shorter. Remove the libraries we no longer need, and add the
non-prebuilt libstd and libtest to the deps generated for every test.

Bug: 153463188
Test: Soong tests pass.
Change-Id: I94f7b514797ab8d6aedb543ea6afdb07611b7293

rust/rust_test.go

@@ -215,25 +215,6 @@ func TestProcMacroDeviceDeps(t *testing.T) {
 			srcs: ["foo.rs"],
 			crate_name: "bar",
 		}
-		// Make a dummy libstd to let resolution go through
-		rust_library_dylib {
-			name: "libstd",
-			crate_name: "std",
-			srcs: ["foo.rs"],
-			no_stdlibs: true,
-		}
-		rust_library_dylib {
-			name: "libterm",
-			crate_name: "term",
-			srcs: ["foo.rs"],
-			no_stdlibs: true,
-		}
-		rust_library_dylib {
-			name: "libtest",
-			crate_name: "test",
-			srcs: ["foo.rs"],
-			no_stdlibs: true,
-		}
 		rust_proc_macro {
 			name: "libpm",
 			rlibs: ["libbar"],