title: gRPC library is installed but doesn't work
body: <p>I'm having a error with google Firestore PHP Api, when I try to connect to Firestore the server return me this error: <code>The requested client requires the gRPC extension. Please see https://cloud.google.com/php/grpc for installation instructions</code>. The error comes from  <code>vendor/google/cloud/Core/src/ClientTrait.php</code> because the function isGrpLoaded response with a false:</p>
  
  <pre><code>/**
   * Abstract the checking of the grpc extension for unit testing.
   *
   * @codeCoverageIgnore
   * @return bool
   */
  protected function isGrpcLoaded()
  {
      return extension_loaded('grpc');
  }
  </code></pre>
  
  <p>I already installed gRPC following this instructions from google <a href="https://cloud.google.com/php/grpc" rel="noreferrer">https://cloud.google.com/php/grpc</a>. I install PECL, install Composer, install the gRPC extension, add the grpc extension to php.ini file, install the Protobuf Runtime library and also add the protobuf extension to php.ini.</p>
  
  <p>So in my composer I have this lines:</p>
  
  <pre><code>...
  google/grpc-gcp                       0.1.3    gRPC GCP library for channel management
  google/protobuf                       v3.6.1   proto library for PHP
  grpc/grpc                             1.15.0   gRPC library for PHP
  ...
  </code></pre>
  
  <p>In my php.ini file I have this two new lines:</p>
  
  <pre><code>extension=protobuf.so
  extension=grpc.so
  </code></pre>
  
  <p>The problem comes here, when I execute in my server terminal this line:</p>
  
  <pre><code>sudo php -r "echo extension_loaded('grpc') ? 'yes' : 'no';"
  </code></pre>
  
  <p>the server response me with a <code>yes</code>, everything seems fine. </p>
  
  <p>But if I create an php file like this:</p>
  
  <pre><code>&lt;?php
    echo extension_loaded('grpc') ? 'yes' : 'no';
  ?&gt;
  </code></pre>
  
  <p>The response is <code>no</code>.</p>
  
  <p>I'm using </p>
  
  <pre><code>Ubuntu 16.04.5 LTS 
  PHP 7.2.13
  </code></pre>