compile_multilib: both for libbinder RPC tests

Needed to add suffixes and update the test that relied on knowing the
path/name of binaries on device.

Test: none
Bug: 355046194
Change-Id: If1af4e5adebb6cd492639813037d236c7ef0fe8a

Author: devinmoore-goog

libs/binder/tests/Android.bp

@@ -235,6 +235,16 @@ cc_defaults {
         "binder_test_defaults",
     ],
 
+    compile_multilib: "both",
+    multilib: {
+        lib32: {
+            suffix: "32",
+        },
+        lib64: {
+            suffix: "64",
+        },
+    },
+
     static_libs: [
         "libbinder_test_utils",
         "libbinder_tls_static",
@@ -267,7 +277,6 @@ cc_defaults {
     defaults: [
         "binderRpcTest_common_defaults",
     ],
-    compile_multilib: "first",
 
     srcs: [
         "binderRpcTest.cpp",

libs/binder/tests/binderRpcTest.cpp

@@ -19,6 +19,12 @@
 #include <aidl/IBinderRpcTest.h>
 #endif
 
+#if defined(__LP64__)
+#define TEST_FILE_SUFFIX "64"
+#else
+#define TEST_FILE_SUFFIX "32"
+#endif
+
 #include <chrono>
 #include <cstdlib>
 #include <iostream>
@@ -259,7 +265,8 @@ std::unique_ptr<ProcessSession> BinderRpc::createRpcTestSocketServerProcessEtc(
 
     std::string path = GetExecutableDirectory();
     auto servicePath = path + "/binder_rpc_test_service" +
-            (singleThreaded ? "_single_threaded" : "") + (noKernel ? "_no_kernel" : "");
+            (singleThreaded ? "_single_threaded" : "") + (noKernel ? "_no_kernel" : "") +
+            TEST_FILE_SUFFIX;
 
     unique_fd bootstrapClientFd, socketFd;