Add executor for MSP Room transactions (#5901)

Task/Issue URL:
https://app.asana.com/1/137249556945/task/1209959841243986?focus=true

### Description
Use dedicated executor for MSP transactions to prevent thread exhaustion
on Room executors

### Steps to test this PR

_Feature 1_
- [ ]
- [ ]

### UI changes
| Before  | After |
| ------ | ----- |
!(Upload before screenshot)|(Upload after screenshot)|

---------

Co-authored-by: Cristian Monforte <[email protected]>

Author: CrisBarreiro

malicious-site-protection/malicious-site-protection-impl/src/main/kotlin/com/duckduckgo/malicioussiteprotection/impl/MaliciousSiteModule.kt

@@ -32,6 +32,7 @@ import dagger.Provides
 import dagger.SingleInstanceIn
 import java.io.File
 import java.security.MessageDigest
+import java.util.concurrent.Executors
 import java.util.concurrent.TimeUnit.SECONDS
 import javax.inject.Named
 import javax.inject.Qualifier
@@ -56,6 +57,8 @@ class MaliciousSiteModule {
     fun provideMaliciousSiteProtectionDatabase(context: Context): MaliciousSitesDatabase {
         return Room.databaseBuilder(context, MaliciousSitesDatabase::class.java, "malicious_sites.db")
             .addMigrations(*ALL_MIGRATIONS)
+            .setQueryExecutor(Executors.newFixedThreadPool(4))
+            .setTransactionExecutor(Executors.newSingleThreadExecutor())
             .fallbackToDestructiveMigration()
             .build()
     }