Hardcodes namespaces lease timing value to 1.5h

After measuring the response and performance of the workers on
https://gitlab.com/gitlab-org/gitlab-ce/issues/64092, we've decided 1.5
is fine for now. The time can be decreased later in the future when
enforcing the quota limits

Related to https://gitlab.com/gitlab-org/gitlab-ce/issues/64092

app/models/namespace/aggregation_schedule.rb

@@ -6,21 +6,13 @@ class Namespace::AggregationSchedule < ApplicationRecord
 
   self.primary_key = :namespace_id
 
-  DEFAULT_LEASE_TIMEOUT = 3.hours
+  DEFAULT_LEASE_TIMEOUT = 1.5.hours.to_i
   REDIS_SHARED_KEY = 'gitlab:update_namespace_statistics_delay'.freeze
 
   belongs_to :namespace
 
   after_create :schedule_root_storage_statistics
 
-  def self.delay_timeout
-    redis_timeout = Gitlab::Redis::SharedState.with do |redis|
-      redis.get(REDIS_SHARED_KEY)
-    end
-
-    redis_timeout.nil? ? DEFAULT_LEASE_TIMEOUT : redis_timeout.to_i
-  end
-
   def schedule_root_storage_statistics
     run_after_commit_or_now do
       try_obtain_lease do
@@ -28,7 +20,7 @@ class Namespace::AggregationSchedule < ApplicationRecord
           .perform_async(namespace_id)
 
         Namespaces::RootStatisticsWorker
-          .perform_in(self.class.delay_timeout, namespace_id)
+          .perform_in(DEFAULT_LEASE_TIMEOUT, namespace_id)
       end
     end
   end
@@ -37,7 +29,7 @@ class Namespace::AggregationSchedule < ApplicationRecord
 
   # Used by ExclusiveLeaseGuard
   def lease_timeout
-    self.class.delay_timeout
+    DEFAULT_LEASE_TIMEOUT
   end
 
   # Used by ExclusiveLeaseGuard

spec/models/namespace/aggregation_schedule_spec.rb

@@ -7,24 +7,6 @@ RSpec.describe Namespace::AggregationSchedule, :clean_gitlab_redis_shared_state,
 
   it { is_expected.to belong_to :namespace }
 
-  describe '.delay_timeout' do
-    context 'when timeout is set on redis' do
-      it 'uses personalized timeout' do
-        Gitlab::Redis::SharedState.with do |redis|
-          redis.set(described_class::REDIS_SHARED_KEY, 1.hour)
-        end
-
-        expect(described_class.delay_timeout).to eq(1.hour)
-      end
-    end
-
-    context 'when timeout is not set on redis' do
-      it 'uses default timeout' do
-        expect(described_class.delay_timeout).to eq(3.hours)
-      end
-    end
-  end
-
   describe '#schedule_root_storage_statistics' do
     let(:namespace) { create(:namespace) }
     let(:aggregation_schedule) { namespace.build_aggregation_schedule }
@@ -87,21 +69,5 @@ RSpec.describe Namespace::AggregationSchedule, :clean_gitlab_redis_shared_state,
         aggregation_schedule.schedule_root_storage_statistics
       end
     end
-
-    context 'with a personalized lease timeout' do
-      before do
-        Gitlab::Redis::SharedState.with do |redis|
-          redis.set(described_class::REDIS_SHARED_KEY, 1.hour)
-        end
-      end
-
-      it 'uses a personalized time' do
-        expect(Namespaces::RootStatisticsWorker)
-          .to receive(:perform_in)
-          .with(1.hour, aggregation_schedule.namespace_id)
-
-        aggregation_schedule.save!
-      end
-    end
   end
 end