disable virtio-balloon by default for VirtualMachineRawConfig

So that we don't need to add an LL-NDK API to disable it.

To reduce the impact of this change, I've kept the balloon enabled for
rialto and Trusty even though it is likely not needed.

Test: TH
Bug: 369588412
Change-Id: If22280957d735bd40e86b4d43869a4b70a233cd4
diff --git a/android/virtmgr/src/aidl.rs b/android/virtmgr/src/aidl.rs
index 82a5573..79c7d81 100644
--- a/android/virtmgr/src/aidl.rs
+++ b/android/virtmgr/src/aidl.rs
@@ -787,7 +787,7 @@
             boost_uclamp: config.boostUclamp,
             gpu_config,
             audio_config,
-            no_balloon: config.noBalloon,
+            balloon: config.balloon,
             usb_config,
             dump_dt_fd,
         };
diff --git a/android/virtmgr/src/crosvm.rs b/android/virtmgr/src/crosvm.rs
index a385b82..2bfa4e1 100644
--- a/android/virtmgr/src/crosvm.rs
+++ b/android/virtmgr/src/crosvm.rs
@@ -133,7 +133,7 @@
     pub boost_uclamp: bool,
     pub gpu_config: Option<GpuConfig>,
     pub audio_config: Option<AudioConfig>,
-    pub no_balloon: bool,
+    pub balloon: bool,
     pub usb_config: UsbConfig,
     pub dump_dt_fd: Option<File>,
 }
@@ -975,8 +975,7 @@
         .arg("--cid")
         .arg(config.cid.to_string());
 
-    if system_properties::read_bool("hypervisor.memory_reclaim.supported", false)?
-        && !config.no_balloon
+    if system_properties::read_bool("hypervisor.memory_reclaim.supported", false)? && config.balloon
     {
         command.arg("--balloon-page-reporting");
     } else {