Reformat imports to a consistent style for imports

rustfmt.toml configuration:
  imports_granularity = "One"
  group_imports = "One"

runtime/src/accounts_background_service.rs

@@ -2,30 +2,32 @@
 //
 // This can be expensive since we have to walk the append vecs being cleaned up.
 
-use crate::{
-    bank::{Bank, BankSlotDelta, DropCallback},
-    bank_forks::BankForks,
-    snapshot_config::SnapshotConfig,
-    snapshot_package::{AccountsPackageSender, SnapshotType},
-    snapshot_utils::{self, SnapshotError},
-};
-use crossbeam_channel::{Receiver, SendError, Sender};
-use log::*;
-use rand::{thread_rng, Rng};
-use solana_measure::measure::Measure;
-use solana_sdk::{
-    clock::{BankId, Slot},
-    hash::Hash,
-};
-use std::{
-    boxed::Box,
-    fmt::{Debug, Formatter},
-    sync::{
-        atomic::{AtomicBool, Ordering},
-        Arc, RwLock,
+use {
+    crate::{
+        bank::{Bank, BankSlotDelta, DropCallback},
+        bank_forks::BankForks,
+        snapshot_config::SnapshotConfig,
+        snapshot_package::{AccountsPackageSender, SnapshotType},
+        snapshot_utils::{self, SnapshotError},
+    },
+    crossbeam_channel::{Receiver, SendError, Sender},
+    log::*,
+    rand::{thread_rng, Rng},
+    solana_measure::measure::Measure,
+    solana_sdk::{
+        clock::{BankId, Slot},
+        hash::Hash,
+    },
+    std::{
+        boxed::Box,
+        fmt::{Debug, Formatter},
+        sync::{
+            atomic::{AtomicBool, Ordering},
+            Arc, RwLock,
+        },
+        thread::{self, sleep, Builder, JoinHandle},
+        time::{Duration, Instant},
     },
-    thread::{self, sleep, Builder, JoinHandle},
-    time::{Duration, Instant},
 };
 
 const INTERVAL_MS: u64 = 100;
@@ -520,10 +522,12 @@ impl AccountsBackgroundService {
 
 #[cfg(test)]
 mod test {
-    use super::*;
-    use crate::genesis_utils::create_genesis_config;
-    use crossbeam_channel::unbounded;
-    use solana_sdk::{account::AccountSharedData, pubkey::Pubkey};
+    use {
+        super::*,
+        crate::genesis_utils::create_genesis_config,
+        crossbeam_channel::unbounded,
+        solana_sdk::{account::AccountSharedData, pubkey::Pubkey},
+    };
 
     #[test]
     fn test_accounts_background_service_remove_dead_slots() {