Update stubs to work with manageiq-password 1.2.0+

The new gem uses File.read and we were stubbing File.read here, so we need
to be more precise in what we stub so we're now targetting just the migration
class's implementation of reading the file.

Part of ManageIQ/manageiq#22696

db/migrate/20180606155924_move_ansible_container_secrets_into_database.rb

@@ -85,10 +85,14 @@ def update_or_create_authentication!(find_args, update_args)
     auth.update!(update_args)
   end
 
+  def self.read_token(file)
+    File.read(file)
+  end
+
   def request_params
     {
       'Accept'         => "application/json",
-      'Authorization'  => "Bearer #{File.read(TOKEN_FILE)}",
+      'Authorization'  => "Bearer #{self.class.read_token(TOKEN_FILE)}",
       :ssl_ca_cert     => CA_CERT_FILE,
       :ssl_verify_mode => OpenSSL::SSL::VERIFY_PEER
     }

manageiq-schema.gemspec

@@ -21,7 +21,7 @@ Gem::Specification.new do |spec|
   spec.add_dependency "ancestry"
   spec.add_dependency "activerecord-id_regions", "~> 0.3.2"
   spec.add_dependency "linux_admin",             "~> 2.0"
-  spec.add_dependency "manageiq-password",       "< 2"
+  spec.add_dependency "manageiq-password",       ">= 1.2.0", "< 2"
   spec.add_dependency "more_core_extensions",    ">= 3.5", "< 5"
   spec.add_dependency "pg"
   spec.add_dependency "rails",                   ">=6.0.4", "<7.0"

spec/migrations/20180606155924_move_ansible_container_secrets_into_database_spec.rb

@@ -111,7 +111,7 @@
   end
 
   def expect_request
-    expect(File).to receive(:read).with(token_path).and_return("totally-a-token")
+    expect(described_class).to receive(:read_token).with(token_path).and_return("totally-a-token")
     response = double("RequestIO", :read => secret_json)
     expect(uri_stub).to receive(:open).with({
       'Accept'         => "application/json",