Increase hangup timeout for VMs

When the CPU is very busy (e.g. right after boot), VMs may take longer
to fully boot. This change increases the timeout for 3 times. Verified
that it's enough for Pixel devices, at least.

Bug: 266470759
Test: run VM right after boot
Change-Id: I5dc142644d40fb63af9a765fc82efa886f792e84
diff --git a/virtualizationmanager/src/crosvm.rs b/virtualizationmanager/src/crosvm.rs
index c1ac20f..8073807 100644
--- a/virtualizationmanager/src/crosvm.rs
+++ b/virtualizationmanager/src/crosvm.rs
@@ -78,9 +78,9 @@
     /// triggered.
     static ref BOOT_HANGUP_TIMEOUT: Duration = if nested_virt::is_nested_virtualization().unwrap() {
         // Nested virtualization is slow, so we need a longer timeout.
-        Duration::from_secs(100)
+        Duration::from_secs(300)
     } else {
-        Duration::from_secs(10)
+        Duration::from_secs(30)
     };
 }