Require custom permission for non-Microdroid

Running with an os other than "microdroid" should require the
USE_CUSTOM_CONFIG permissions (as do our other @TestApi).

Add check, fix up tests.

Bug: 323513087
Test: atest MicrodroidTestApp MicrodroidHostTestCases
Change-Id: If7bc577b275f2a55c80c302ed00d5947676daa6a
diff --git a/javalib/api/test-current.txt b/javalib/api/test-current.txt
index 0a988d8..36a82f7 100644
--- a/javalib/api/test-current.txt
+++ b/javalib/api/test-current.txt
@@ -16,7 +16,7 @@
 
   public static final class VirtualMachineConfig.Builder {
     method @FlaggedApi("com.android.system.virtualmachine.flags.avf_v_test_apis") @NonNull public android.system.virtualmachine.VirtualMachineConfig.Builder addExtraApk(@NonNull String);
-    method @FlaggedApi("com.android.system.virtualmachine.flags.avf_v_test_apis") @NonNull public android.system.virtualmachine.VirtualMachineConfig.Builder setOs(@NonNull String);
+    method @FlaggedApi("com.android.system.virtualmachine.flags.avf_v_test_apis") @NonNull @RequiresPermission(android.system.virtualmachine.VirtualMachine.USE_CUSTOM_VIRTUAL_MACHINE_PERMISSION) public android.system.virtualmachine.VirtualMachineConfig.Builder setOs(@NonNull String);
     method @NonNull @RequiresPermission(android.system.virtualmachine.VirtualMachine.USE_CUSTOM_VIRTUAL_MACHINE_PERMISSION) public android.system.virtualmachine.VirtualMachineConfig.Builder setPayloadConfigPath(@NonNull String);
     method @FlaggedApi("com.android.system.virtualmachine.flags.avf_v_test_apis") @NonNull @RequiresPermission(android.system.virtualmachine.VirtualMachine.USE_CUSTOM_VIRTUAL_MACHINE_PERMISSION) public android.system.virtualmachine.VirtualMachineConfig.Builder setVendorDiskImage(@NonNull java.io.File);
     method @NonNull public android.system.virtualmachine.VirtualMachineConfig.Builder setVmConsoleInputSupported(boolean);