build: use clang-7. (#4493)

*Risk Level*: Low
*Testing*: Successful build using new image.
*Docs Changes*: n/a
*Release Notes*: n/a

Closes #4477.

Signed-off-by: Piotr Sikora <piotrsikora@google.com>

Mirrored from https://github.com/envoyproxy/envoy @ 6384d76cc4f06454893241d9a7c0146aa81dd5ad

envoy/api/v2/core/health_check.proto

@@ -22,13 +22,19 @@ message HealthCheck {
   // The time to wait for a health check response. If the timeout is reached the
   // health check attempt will be considered a failure.
   google.protobuf.Duration timeout = 1 [
-    (validate.rules).duration = {required: true, gt: {seconds: 0}},
+    (validate.rules).duration = {
+      required: true,
+      gt: {seconds: 0}
+    },
     (gogoproto.stdduration) = true
   ];
 
   // The interval between health checks.
   google.protobuf.Duration interval = 2 [
-    (validate.rules).duration = {required: true, gt: {seconds: 0}},
+    (validate.rules).duration = {
+      required: true,
+      gt: {seconds: 0}
+    },
     (gogoproto.stdduration) = true
   ];
 

envoy/config/filter/http/buffer/v2/buffer.proto

@@ -19,8 +19,13 @@ message Buffer {
 
   // The maximum number of seconds that the filter will wait for a complete
   // request before returning a 408 response.
-  google.protobuf.Duration max_request_time = 2
-      [(validate.rules).duration = {required: true, gt: {}}, (gogoproto.stdduration) = true];
+  google.protobuf.Duration max_request_time = 2 [
+    (validate.rules).duration = {
+      required: true,
+      gt: {}
+    },
+    (gogoproto.stdduration) = true
+  ];
 }
 
 message BufferPerRoute {