Enable InternalImportsByDefault in remaining modules (#2042)

This PR enables `InternalImportsByDefault` on `GRPCHealth` and
`InteroperabilityTests`.
It also regenerates the protos with the latest version of swift-protobuf
(v1.28.1), and increases its min version to 1.28.1 to make sure that we
don't get build failures when using earlier generators.

Author: gjcairo

Sources/InteroperabilityTests/Generated/empty.pb.swift

@@ -22,7 +22,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-import SwiftProtobuf
+public import SwiftProtobuf
 
 // If the compiler emits an error on this type, it is because this file
 // was generated by a version of the `protoc` Swift plug-in that is

Sources/InteroperabilityTests/Generated/messages.pb.swift

@@ -24,8 +24,8 @@
 
 // Message definitions to be used by integration test service definitions.
 
-import Foundation
-import SwiftProtobuf
+public import Foundation
+public import SwiftProtobuf
 
 // If the compiler emits an error on this type, it is because this file
 // was generated by a version of the `protoc` Swift plug-in that is

Sources/InteroperabilityTests/InteroperabilityTestCase.swift

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-import GRPCCore
+public import GRPCCore
 
 @available(macOS 15.0, iOS 18.0, watchOS 11.0, tvOS 18.0, visionOS 2.0, *)
 public protocol InteroperabilityTest {

Sources/InteroperabilityTests/InteroperabilityTestCases.swift

@@ -14,9 +14,9 @@
  * limitations under the License.
  */
 
-import GRPCCore
+internal import GRPCCore
 
-import struct Foundation.Data
+private import struct Foundation.Data
 
 /// This test verifies that implementations support zero-size messages. Ideally, client
 /// implementations would verify that the request and response were zero bytes serialized, but

Sources/InteroperabilityTests/TestService.swift

@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-import Foundation
-import GRPCCore
+private import Foundation
+public import GRPCCore
 
 @available(macOS 15.0, iOS 18.0, watchOS 11.0, tvOS 18.0, visionOS 2.0, *)
 public struct TestService: Grpc_Testing_TestService.ServiceProtocol {

Sources/Services/Health/Generated/health.pb.swift

@@ -25,7 +25,7 @@
 // The canonical version of this proto can be found at
 // https://github.com/grpc/grpc-proto/blob/master/grpc/health/v1/health.proto
 
-import SwiftProtobuf
+package import SwiftProtobuf
 
 // If the compiler emits an error on this type, it is because this file
 // was generated by a version of the `protoc` Swift plug-in that is