The Esri lib is probably automatically getting added because we have are adding it via qmake in the arcgis_runtime_qml10_2_6.prf file. So even if you remove it, each time qmake runs, it gets added back due to this line getting executed -
ANDROID_EXTRA_LIBS = $${SDK_INSTALL_DIR}/sdk/$${PLATFORM}/armv7/lib/libEsriRuntimeQt.so
Now that I am looking at it, I wonder if this line needs to get changed to use += instead of =
ANDROID_EXTRA_LIBS += $${SDK_INSTALL_DIR}/sdk/$${PLATFORM}/armv7/lib/libEsriRuntimeQt.so
This could be blowing it out every time because it is using the assignment operator. I see that is something that we fixed in our new templates (v 100). Can you try going into the following file and fixing that? <qt kit location>\mkspecs\features\arcgis_runtime_qml10_2_6.qml