How do I declare the OpenGL version in shaders on Android?

How do I declare the OpenGL version in shaders on Android?

I'm experimenting with OpenGL ES 3.0 and found the following statement in
the Quick Reference sheet:
"#version 300 es" must appear in the first line of a shader program
written in GLSL ES version 3.00. If omitted, the shader will be treated as
targeting version 1.00.
So I tried to add this at the beginning of my shaders, but that only
resulted in the error
Link failed because of invalid vertex shader.
as reported by .glGetProgramInfoLog. If I remove the first line with the
"#version 300 gl" statement, the shader compiles and works.
This is the code of my vertex shader
private final String vertexShaderCode =
"#version 300 es \n" +
"uniform mat4 uMVPMatrix; \n" +
"attribute vec2 a_TexCoordinate; \n" +
"attribute vec4 vPosition; \n" +
"varying vec2 v_TexCoordinate; \n" +
"void main() { \n" +
" v_TexCoordinate = a_TexCoordinate; \n" +
" gl_Position = uMVPMatrix * vPosition; \n" +
"} \n";
I also added the version statement to the vertex and the fragment shader,
and still get the same error.
I call setEGLContextClientVersion(3) in my GLSurfaceView, and I added
<uses-feature android:glEsVersion="0x00030000" android:required="true" />
to my manifest to indicate that the app requires OpenGL ES 3.0.
Am I reading the OpenGL ES documentation wrong and I don't need to add
this version statement? If I need to add it, what am I doing wrong that it
always results in an error?