Fixup spec stubs for backup, restore

Update parameters a little bit. They still aren't totally right but this
is a minor improvement.

Author: reidmv

spec/plans/backup_spec.rb

@@ -2,7 +2,7 @@
 
 describe 'peadm::backup' do
   include BoltSpec::Plans
-  let(:params) { { 'primary_host' => 'primary' } }
+  let(:params) { { 'targets' => 'primary' } }
 
   it 'runs with default params' do
     allow_apply

spec/plans/restore_spec.rb

@@ -2,7 +2,7 @@
 
 describe 'peadm::restore' do
   include BoltSpec::Plans
-  let(:params) { { 'primary_host' => 'primary', 'backup_timestamp' => '2022-03-29_16:57:41' } }
+  let(:params) { { 'targets' => 'primary', 'backup_timestamp' => '2022-03-29_16:57:41' } }
 
   it 'runs with default params' do
     allow_apply